Systems and methods for electronic dive table planner

Abstract

Aspects of the present disclosure include an easy to use electronic no-decompression table for use in recreational dive planning in order to avoid decompression sickness. In one embodiment, the electronic no-decompression calculator is a portable handheld unit. The user is requested to enter at least one relevant piece of information about a dive and that information is used to automatically compute depth, bottom time, and surface interval time limits as well as pressure group categorizations. In one embodiment, an information tablet is provided with information relevant to planning a dive.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings and the associated descriptions are provided to illustrate embodiments of the disclosure and not to limit the scope of the claims.

FIG. 1 illustrates a front plan view of one embodiment of an electronic no-decompression calculator in its packaging.

FIG. 2 illustrates a back plan view of the packaging of FIG. 1 showing instructions for use.

FIG. 3 illustrates the embodiment of FIG. 1 with the electronic no-decompression calculator and the instructions for use outside of its packaging.

FIG. 4 illustrates a front view of an electronic no-decompression calculator with attached instruction tablet.

FIG. 5 illustrates a perspective view of an electronic no-decompression calculator with attached instruction tablet.

FIG. 6 illustrates a back view of an electronic no-decompression calculator with attached instruction tablet.

FIG. 7 illustrates a back view of an electronic no-decompression calculator with attached instruction tablet and battery cover removed.

FIG. 8 illustrates a front view of an electronic no-decompression calculator.

FIG. 9A illustrates a front view of an instruction tablet.

FIG. 9B illustrates a back view of an instruction tablet.

FIG. 10 illustrates a flowchart of the operation of one embodiment of a no-decompression calculator.

FIG. 11 illustrates a flowchart of a dive planning module of one embodiment of a no-decompression calculator.

FIGS. 12A and 12B illustrate a flowchart of a surface interval module of one embodiment of a no-decompression calculator.

FIG. 13 illustrates a flow chart of one embodiment of a maximum depth module of one embodiment of a no-decompression calculator.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Embodiments of the present disclosure include a recreational electronic dive no-decompression calculator for use in planning underwater dives, including SCUBA dives. A diver prepares for his/her dive by first determining dive limitations in order to avoid decompression sickness. A diver enters information regarding a dive into the calculator and receives in response limitations and warnings on a planned dive. In one embodiment the no-decompression calculator aids in determining a no decompression time limit. In one embodiment, the no-decompression calculator calculates a pressure group after a dive. In one embodiment, the no-decompression calculator determines a pressure group after a surface interval. In one embodiment, the no-decompression calculator determines a minimum surface interval. In one embodiment, the no-decompression calculator determines a maximum depth. In one embodiment, the no-decompression calculator warns of an exceeded limit. In one embodiment, no-decompression calculator warns of a necessary decompression stop.

FIG. 1 illustrates one embodiment of a kit 100 containing a no-decompression calculator 101 in its packaging 103. FIG. 2 illustrates the backside of the packaging of FIG. 1. As illustrated in FIG. 2, kit 100 contains instructions for use 205. FIG. 3 illustrates a view of kit 100 with kit components 101, 103, 205, 307 separated. FIG. 3 also illustrates tablet 307 operably coupled to an electronic no-decompression calculator 101.

FIG. 4 illustrates one embodiment of an electronic no-decompression calculator 101 with coupled tablet 307. Tablet 307 includes text 407. Text 407 includes warnings, reminders, helpful hints, and instructions for planning a dive. In one embodiment, the tablet 307 contains the following copyrighted information:

General Rules for Using the eRDP

• • 1. The Electronic Recreational Dive Planner (eRDP) is designed specifically for planning recreational (no-decompression) dives on air only. Do not attempt to use it for planning decompression dives.
  • 2. Safety Stops—A safety stop for 3 minutes at 5 metres/15 feet is required any time the diver comes within 3 pressure groups of a no-decompression limit, and for any dive to a depth of 30 metres/100 feet or greater.
  • 3. Emergency Decompression—If a no-decompression limit is exceeded by no more than 5 minutes, an 8 minute decompression stop at 5 metres/15 feet is mandatory. Upon surfacing, the diver must remain out of the water for at least 6 hours prior to making another dive. If a no-decompression limit is exceeded by more than 5 minutes, a 5 metres/15 feet decompression stop of no less than 15 minutes is urged (air supply permitting). Upon surfacing, the diver must remain out of the water for at least 24 hours prior to making another dive.
  • 4. Flying after Diving Recommendations
    • For Dives within the No-Decompression Limits
      • Single Dives: A minimum preflight surface interval of 12 hours is suggested.
      • Repetitive Dives and/or Multi-Day Dives: A minimum preflight surface interval of 18 hours is suggested.
    • For dives requiring decompression stops
      • A minimum preflight surface interval of greater than 18 hours is suggested
  • 5. Diving at Altitude—Diving at Altitude (300 metres/1000 feet or greater) requires use of special training and procedures.
  • 6. Special Rules for Multiple Dives
  •  If you are planning 3 or more dives in a day: Beginning with the first dive, if your ending pressure group after any dive is W or X, the minimum surface interval between all subsequent dives is 1 hour. If your ending pressure group after any dive is Y or Z, the minimum surface interval between all subsequent dives is 3 hours. Note: since little is known about the physiological effects of multiple dives over multiple days, divers are wise to make fewer dives and limit their exposure toward the end of a Multi-Day dive series.
  • 7. Ascend from all dives at a rate not to exceed 18 metres/60 feet per min.
  • 8. When planning a dive in cold water or under conditions that might be strenuous, plan the dive assuming the depth is 4 metres/10 feet deeper than actual.
  • 9. Plan repetitive dives so each successive dive is to a shallower depth. Limit repetitive dives to 30 metres/100 feet or shallower.
  • 10. Do not dive below 40 metres/130 feet. As an emergency procedure, if you discover you have accidentally descended below 40 metres/130 feet, immediately ascend (at a rate not to exceed 18 metres/60 feet per minute) to 5 metres/15 feet and make an emergency decompression stop for 8 minutes. Any dive below 40 metres/130 meet must be followed by a surface interval of at least 6 hours.
  • 11. When the eRDP reads “SEE RULE 11,” your residual nitrogen levels are so low that you may plan your next dive as a first dive. The WX and YZ rules for minim surface intervals when making more than three dives in a day still apply.”© Diving Science and Technology 1985-2006The information on the tablet can be on the front or back of the tablet and in any color, shape, size, orientation or font. A person of ordinary skill in the art will recognize from the disclosure herein that more or fewer warnings, reminders, helpful hints, and instructions can be placed on the tablet.

Tablet 307 is operably coupled to electronic no-decompression calculator 101 by ring 401. Ring 401 operably couples to integrally molded rings 403, 405 on the electronic no-decompression calculator 101 and tablet 307 respectively. Although tablet 307 and electronic no-decompression calculator 101 can be directly connected without ring 401, the ring 401 allows for greater movement of tablet 307 relative to the electronic no-decompression calculator 101. In one embodiment, the ring 401 is removable such that the tablet 307 and electronic no-decompression calculator 101 can be separated. In one embodiment, ring 401 is not removable. In one embodiment, tablet 307 and electronic no-decompression calculator 101 are not connected or connectable. In one embodiment, the tablet 307 is a cover. The tablet cover can be removable or permanently attached to the electronic no-decompression calculator. In one embodiment, the tablet cover is slidably detachable through the use of male and female guide channels. In one embodiment, the tablet cover is rotatably connected to the electronic no-decompression calculator 101 by a hinge, such that the cover can be flipped open. It will be understood by a person of skill in the art that other connectors beside ring 401 and integrally molded rings 403, 405 can be used. For example, Velcro, screws, glue, magnets, or other permanent or temporary fasteners can be used to couple together the tablet and the electronic no-decompression calculator. Other connectors will be apparent to those of ordinary skill in the art from the present disclosure.

In one embodiment, the electronic no-decompression calculator is not associated with a tablet, rather the tablet 307 is integrated into the housing of the electronic no-decompression calculator 101. In one embodiment, the information that would be located on the tablet 307 is located on the back of the electronic no-decompression calculator 101. In one embodiment, the information of the tablet is incorporated into the memory of the electronic no-decompression calculator, such that the information is electronically displayed to the user during use.

FIG. 5 illustrates a perspective view of one embodiment of an electronic dive calculator 101 and tablet 307. The electronic dive calculator 101 and tablet 307 can be relatively thin and small. In one embodiment the electronic dive calculator 101 is less than about 4½ inches wide, less than about 2⅞ inches high, and less than about ½ inch thick. In one embodiment, the electronic dive calculator 101 is less than about ⅜ inch thick. In one embodiment, the tablet is about 4½ inches wide, about 2⅞ inches high, and about ⅛ inch deep.

FIG. 6 illustrates a back view of both the electronic no-decompression calculator 101 and the tablet 307. Electronic no-decompression calculator 101 has a battery cover 601 which holds and protects the battery held within the electronic no-decompression calculator. The cover can be either rotated closed at position 603 or rotated open at position 605. To aid in rotating the battery cover, slot 607 is provided. Electronic no-decompression calculator 101 also has non-skid pads 609. Non-skid pads 609 can be made from rubber or any other material suitable for providing traction for the electronic no-decompression calculator.

FIG. 7 illustrates a back view of the electronic no-decompression calculator 101 with battery cover 601 removed. The battery cover has male channel connectors 705 which operate in connection with female channel connectors 706. As illustrated, under the battery cover 601, are hidden a reset button 701 and a FEET/METER (FT/M) switch 703. The reset button 701 allows a user to manually reset the electronic no-decompression calculator. The FT/M switch 703 allows a user to switch between using the imperial measurement system and the metric measurement system.

FIG. 8 illustrates a closer view of the front of one embodiment of the electronic no-decompression calculator 101. Electronic no-decompression calculator 101 has a display 801, buttons 803, display reference 805, and housing 807. In one embodiment, the display 801 is an electroluminescent, LED or LCD display. In one embodiment, the display displays both words and numbers. In one embodiment, the display flashes in order to highlight what is displayed. In one embodiment, the display has a background light in order to provide light when other light sources are not available. In one embodiment, the display is black and white. In one embodiment, the display is color. In one embodiment, the display displays graphics or other trend or history information.

Buttons 803 provide a means for achieving user input of information to the electronic no-decompression calculator. The buttons 803 include alphanumeric buttons containing numbers 0-9 and letters A-Z. The buttons 803 also include a Yes button and a No button as well as a Mode/Reset button, a Delete button, a Back button, and an Enter button.

Display reference 805 is a quick reference guide to acronyms displayed on the display 801. The acronyms include “SI—SURFACE INTERVAL,” “ABT—ACTUAL BOTTOM TIME,” “PG—PRESSURE GROUP,” “NDL—NO DECOMPRESSION LIMIT.” In operation, for example, when the calculator displays a minimum surface interval time, it will display “MIN SI ##H:##M.” The display reference 805 provides a quick display reminder for commonly used acronyms used by the display.

FIGS. 9A and 9B illustrate a closer front and back view of the tablet 307.

FIG. 10 illustrates a flowchart of the operation of one embodiment of an electronic no-decompression calculator 101. At block 1001, the calculator is turned on. The process then moves to block 1003 where a welcome screen is displayed. The welcome screen displays the product name, the unit of measure, and then requests the user to select a mode of operation. In one embodiment, only a single mode of operation is available, and the welcome screen takes the user directly to that mode of operation. In one embodiment two or more modes of operation are available and a user must choose which mode they wish to utilize. In one embodiment, three modes of operations are available. A user then uses the Mode/Reset button in order to select between one of the modes of operation. In one embodiment, for example, in the embodiment of FIG. 10, the three modes of operation are Dive Planning, Surface Interval, and Maximum Depth. Other modes will be apparent to a person of skill in the art from the present disclosure. The user then uses the Enter button in order to select the desired mode.

The system then moves onto decision block 1004 where a user selects one of the modes of operation. According to which mode is selected, the process then continues on to one of three module blocks: Dive Planning module 1005, Surface Interval module 1007, or Maximum Depth module 1009, the operation of these modules are described in further detail below. From the module blocks, the process either ends at block 1011 where the calculator is turned off manually by the user, or automatically after a predetermined period of time, or the processor returns to welcome block 1003 after a user reset has occurred.

FIG. 11 illustrates a flow chart of the dive planning module 1005. The dive planning module begins at block 1101 where the user is asked whether this is his/her first dive of the day. If the answer is yes, the system moves onto block 1103 where the user is asked to enter a bottom depth. If the answer is no, the system moves onto block 1104 where the user is asked whether the user knows his/her pressure group after the surface interval. If the answer is yes, then the system moves on to block 1105 where the user is asked to enter his/her pressure group at the start of the dive. From block 1105, the system then moves on to decision block 1107 where the system decides if the pressure group is W, X, Y, or Z. If the pressure group is W, X, Y, or Z, then the system moves on to block 1109 where the system displays a warning message to see rule 6 on tablet 307. Rule 6 is quoted above and shown in FIG. 9B. Once the warning message is displayed and acknowledged by the user, such as, for example by using the enter button, the system moves on to block 1103. If at decision block 1107, the pressure group is not W, X, Y, or Z, then the system moves on to block 1103.

If at block 1104, the answer is no, then the system moves on to block 1106 where the user is asked to enter his/her pressure group before the surface interval. The system then moves to block 1108, where the system decides if the pressure group is W, X, Y, or Z. If the pressure group is not W, X, Y, or Z, then the system moves on to block 1112. If the pressure group is W, X, Y, or Z, then the system moves on to block 1110 where the system displays a warning message to see rule 6. Once the warning message is displayed and acknowledged by the user, the system moves on to block 1112. At block 1112, the user is asked to enter the surface interval time period. Once entered, the system computes the pressure group after the surface interval at block 1114. The system then decides if the pressure group is W, X, Y, or Z. If the pressure group is not W, X, Y, or Z, then the system moves on to block 1120. If the pressure group is W, X, Y, or Z, then the system moves on to block 1118 where the system displays a warning message to see rule 6. Once the warning message is displayed and acknowledged by the user, the system moves on to block 1120. At block 1120, the system displays the pressure group after the surface interval, and once acknowledged by the user, the system moves on to block 1103.

At block 1103, the user is asked to enter a bottom depth. Once entered, the system moves on to decision block 1111. At decision block 1111, the system decides whether the depth entered is greater than 30 meters or 100 feet. If the depth is not greater than 30 meters or 100 feet, the system moves on to block 1113. If the depth is greater than 30 meters or 100 feet, the system moves on to decision block 1115 where the system decides whether the depth is greater than 40 meters or 130 feet. If the depth is not greater than 40 meters or 130 feet, then the system displays a warning message to see rule 2 at block 1117 and waits for a user acknowledgment before moving on to block 1113. If at decision block 1115, the system determines the depth is greater than 40 meters or 130 feet, then the system moves onto block 1119, where the system displays a warning message to see rule 10 as quoted above and shown in FIG. 9B. Once the warning message is acknowledged by the user, the system returns to block 1103.

At block 1113, the calculator computes and displays the no decompression time limit for the given depth and pressure group. Once the user acknowledges the displayed no decompression time limit, the system moves on to block 1121, where the user is asked to enter the actual bottom time associated with the previously entered depth. Once entered the system moves on to decision block 1123, where the system determines if the no decompression time limit has been exceeded. If the no decompression time limit has not been exceeded, then the system moves on to block 1126. If at decision block 1123 the no decompression time limit has been exceeded, then the system moves on to block 1125 where the system displays an exceeds limits warning message and, once acknowledged by the user, the system returns to block 1121.

At block 1126, the system computes the pressure group after the dive. The system then moves on to decision block 1127, where the system determines if the computed pressure group is within 3 of the no decompression limit. If the computed pressure group is not within 3 of the no decompression limit, then the system moves on to block 1131 where the pressure group after the dive is displayed. If at decision block 1127 the computed pressure group is within 3 of the no decompression limit, then the system moves on to block 1129 where the system displays a warning message to see rule 2 as quoted above and shown in FIG. 9A. Once acknowledged by the user, the system moves on to block 1131.

After the user acknowledges the displayed pressure group after the dive, the system moves on to block 1132 where the system determines whether the pressure group before the surface interval is W, X, Y, or Z. If the pressure group before the surface interval is not W, X, Y, or Z, then the system moves on to block 1133, where the user is asked to enter a desired surface interval. If at decision block 1132, the pressure group before the surface interval is W, X, Y, or Z, then the system moves on to block 1134 where the system displays a warning message to see rule 6 as quoted above and shown in FIG. 9B. Once acknowledged by the user, the system then moves on to block 1133 as described above.

The system then moves on to block 1135 where the system computes the pressure group after the desired surface interval. Once acknowledged by the user, the system moves on to decision block 1137, where the system determines whether the pressure group after the surface interval is W, X, Y, or Z. If the pressure group after the surface interval is not W, X, Y, or Z, then the system moves on to block 1141 where the system displays the pressure group after the surface interval. If at decision block 1137, the pressure group after the surface interval is W, X, Y, or Z, then the system moves on to block 1139 where the system displays a warning message to see rule 6 as quoted above and shown in FIG. 9B. Once acknowledged by the user, the system then moves on to block 1141.

After the user acknowledges the pressure group displayed after the surface interval at block 1141, the system returns to block 1103 and the process is repeated. In one embodiment, the process is repeated 5 times. In one embodiment, the process is repeated more than 5 times. In one embodiment, the process is repeated less than 5 times. In one embodiment, the process is not repeated.

FIGS. 12A and 12B illustrate a flow chart of one embodiment of a surface interval module. The surface interval module begins at block 1201 where the user is asked whether this is his/her first dive of the day. If the answer is yes, the system moves onto block 1203 where the user is asked to enter a bottom depth of his/her first dive. If at block 1201, the answer is no, the system moves on to block 1206 where the user is asked to enter his/her pressure group after the first dive. The system then moves on to decision block 1208 where the system decides if the pressure group is W, X, Y, or Z. If the pressure group is W, X, Y, or Z, then the system displays a warning message to see rule 6 at block 1210. Once the warning message is acknowledged by the user, the system moves on to block 1223. If at decision block 1208, the pressure group is not W, X, Y, or Z, then the system moves directly on to block 1223.

At block 1203, the user is asked to enter a bottom depth of his/her first dive. Once entered, the system moves on to decision block 1205. At decision block 1205, the system decides whether the depth entered is greater than 30 meters or 100 feet. If the depth is not greater than 30 meters or 100 feet, the system moves on to block 1213. If the depth is greater than 30 meters or 100 feet, the system moves on to decision block 1207 where the system decides whether the depth is greater than 40 meters or 130 feet. If the depth is not greater than 40 meters or 130 feet, then the system displays a warning message to see rule 2 at block 1211 and waits for a user acknowledgment before moving on to block 1213. If at decision block 1207, the system determines the depth is greater than 40 meters or 130 feet, then the system moves onto block 1209, where the system displays a warning message to see rule 10 as quoted above and shown in FIG. 9B. Once the warning message is acknowledged by the user, the system returns to block 1203.

At block 1213, the system computes and displays the no decompression time limit for the given depth and pressure group. Once the user acknowledges the displayed no decompression time limit, the system moves on to block 1214, where the user is asked to enter the actual bottom time of the first dive. Once entered the system moves on to decision block 1215, where the system determines if the no decompression time limit has been exceeded. If the no decompression time limit has not been exceeded, then the system moves on to decision block 1216. If at decision block 1215 the no decompression time limit has been exceeded, then the system moves on to block 1217 where the system displays an exceeds limits warning message and, once acknowledged by the user, the system returns to block 1214.

At block 1216, the system computes the pressure group after the first dive. The system then moves on to decision block 1219, where the system determines if the computed pressure group is within 3 of the no decompression limit. If the computed pressure group is not within 3 of the no decompression limit, then the system moves on to block 1223. If at decision block 1219 the computed pressure group is within 3 of the no decompression limit, then the system moves on to block 1221 where the system displays a warning message to see rule 2 as quoted above and shown in FIG. 9A. Once acknowledged by the user, the system moves on to block 1223.

At block 1223, the user is asked to enter the bottom depth of the second dive. Once entered, the system moves on to decision block 1225. At decision block 1225, the system decides whether the depth entered is greater than 30 meters or 100 feet. If the depth is not greater than 30 meters or 100 feet, the system moves on to block 1233. If the depth is greater than 30 meters or 100 feet, the system moves on to decision block 1227 where the system decides whether the depth is greater than 40 meters or 130 feet. If the depth is not greater than 40 meters or 130 feet, then the system displays the message to see rule 2 at block 1231 and waits for a user acknowledgment before moving on to block 1233. If at decision block 1227, the system determines the depth is greater than 40 meters or 130 feet, then the system moves onto block 1229, where the system displays a warning message to see rule 10 as quoted above and shown in FIG. 9B. Once the warning message is acknowledged by the user, the system returns to block 1223.

At block 1233, the system computes and displays the no decompression time limit for the second dive. Once the user acknowledges the displayed no decompression time limit, the system moves on to block 1235, where the user is asked to enter the actual bottom time of the second dive. Once entered the system moves on to decision block 1237, where the system determines if the no decompression time limit has been exceeded. If the no decompression time limit has not been exceeded, then the system moves on to block 1240. If at decision block 1237 the no decompression time limit has been exceeded, then the system moves on to block 1239 where the system displays an exceeds limits warning message and, once acknowledged by the user, the system returns to block 1235.

At block 1240, the system computes the pressure group after the second dive and then moves on to decision block 1241 where the system determines whether the pressure group after the second dive is within 3 of the no decompression limit. If the pressure group is not within 3 of the no decompression limit, then the system moves on to block 1245. If at decision block 1241, the pressure group after the second dive is within 3 of the no decompression limit, then the system moves on to block 1243, where the system displays a warning message to see rule 2. Once acknowledged by the user the system moves on to block 1245. At block 1245 the system computes and displays the minimum surface interval.

FIG. 13 illustrates a flow chart of one embodiment of a maximum depth module 1009. The system begins at block 1301, where the user is asked if this is his/her first dive. If the answer is yes, the system moves on to block 1305. If the answer is no, the system moves on to block 1303, where the user is asked to enter his/her pressure group after his/her surface interval. Once entered, the system moves on to block 1305. At block 1305, the user is asked to enter his/her desired dive time. Once entered, the system moves on to block 1307 where the system computes the maximum depth for the dive time and pressure group. The system then moves on to decision block 1309, where the system determines whether the maximum time limits have been exceeded. If the maximum time limits have been exceeded, then the system moves on to block 1311 where the system displays a limits exceeded message and, once acknowledged by the user, returns to block 1305. If at block 1309, the maximum time limits have not been exceeded, then the system moves on to block 1313, where the system displays a warning message to see rule 2. Once the user acknowledges the rule 2 warning message, then the system moves on to block 1315 where the maximum depth is displayed.

Although the foregoing invention has been described in terms of certain preferred embodiments, other embodiments will be apparent to those of ordinary skill in the art from the disclosure herein. Additionally, other combinations, omissions, substitutions and modifications will be apparent to the skilled artisan in view of the disclosure herein. It is contemplated that various aspects and features of the invention described can be practiced separately, combined together, or substituted for one another, and that a variety of combination and subcombinations of the features and aspects can be made and still fall within the scope of the invention. Furthermore, the systems described above need not include all of the modules and functions described in the preferred embodiments. Accordingly, the present invention is not intended to be limited by the recitation of the preferred embodiments, but is to be defined by reference to the appended claims.

Claims

1. An automated method of planning an underwater dive, the method comprising: entering a first pressure group;entering a depth;automatically determining a no decompression time limit using the first pressure group and the depth;automatically displaying the no decompression time limit on a user readable display;entering a first time period corresponding to an actual bottom time;automatically determining a second pressure group using the first pressure group, the depth and the time;automatically displaying the second pressure group on the user readable display;entering a second time period corresponding to a surface interval;automatically determining a third pressure group using the first pressure group, the first depth, the first time period and the second time period; andautomatically displaying the third pressure group on the user readable display.

2. The automated method of claim 1, further comprising: automatically determining at least one warning message; andautomatically displaying the at least one warning message on the user readable display.

3. The automated method of claim 1, further comprising: entering a second depth;automatically determining a second no decompression time limit using the third pressure group and the second depth; andautomatically displaying the second no decompression time limit on the user readable display.

4. The automated method of claim 3, further comprising: entering a third time period corresponding to an actual bottom time;automatically determining a fourth pressure group using the third pressure group, the second depth and the third time period; andautomatically displaying the fourth pressure group on the user readable display.

5. The automated method of claim 4, further comprising: entering a fourth time period corresponding to a surface interval;automatically determining a fifth pressure group using the third pressure group, the second depth, the third time period and the fourth time period.automatically displaying the fifth pressure group on the user readable display.

6. An automated method of planning an underwater dive, the automated method comprising: entering a depth;entering a first time period;automatically determining a no decompression time limit using the depth and the first time period;automatically displaying the no decompression time limit on a user readable display.

7. The automated method of claim 6, further comprising: automatically determining and displaying a warning message; andautomatically displaying the warning message on the user readable display.

8. The automated method of claim 6, further comprising using a handheld electronic device configured to automatically determine and display the no decompression time limit using the depth and the first time period.

9. An automated method of determining a surface interval between underwater dives, the method comprising: entering a first depth;entering a first time period corresponding to a bottom time associated with the first depth;entering a second depth;entering a second time period corresponding to a bottom time associated with the second depth;automatically computing a third time period corresponding to a surface interval using the first and second depths and the first and second time periods; andautomatically displaying the third time period on a user readable display.

10. The automated method of claim 9, further comprising automatically determining and displaying a first no decompression time limit using the first depth.

11. The automated method of claim 9, further comprising automatically determining and displaying a second no decompression time limit using the first and second depths and the first time period.

12. The automated method of claim 9, further comprising determining and displaying at least one warning message.

13. An automated method of determining a maximum depth in preparation for an underwater dive, the method comprising: entering a first time period;automatically determining and displaying a maximum depth using the first time period; andautomatically displaying the maximum depth on a user readable display.

14. The automated method of claim 13, further comprising: entering a first pressure group; andwherein automatically determining a maximum depth further comprises using the first pressure group.

15. The automated method of claim 13, further comprising determining and displaying at least one warning message.

16. A handheld electronic no-decompression underwater dive planner comprising: a housing;a display operably connected to the housing;a user input control for entering one or more user inputs; anda processor configured to output to the display information relevant in planning an underwater dive based on the user input control.

17. The handheld electronic no-decompression planner of claim 16, wherein the user input control comprises alphanumeric buttons.

18. The handheld electronic no-decompression planner of claim 16, wherein the display comprises a liquid crystal display.

19. The handheld electronic no-decompression planner of claim 16, wherein the housing is water resistant.

20. The handheld electronic no-decompression planner of claim 16, wherein information comprises at least one of a no-decompression time limit, a pressure group, a surface interval, and a depth.

21. The handheld electronic no-decompression planner of claim 16, wherein user inputs comprises at least one of a pressure group, a depth, an at depth time period, and a surface interval time period.

22. The handheld electronic no-decompression planner of claim 16, further comprising a tablet operably connected to the housing.

23. The handheld electronic no-decompression planner of claim 22, wherein the tablet comprises written information relevant to planning an underwater dive.

24. The handheld electronic no-decompression planner of claim 16, wherein the housing is less than about ½ inch thick.

25. The handheld electronic no-decompression planner of claim 16, wherein the housing is less than about ⅜ inch thick.

26. A kit comprising an electronic no-decompression planner and instructions for use.

27. The kit of claim 26, further comprising a package which contains the electronic no-decompression planner and instructions for use.

28. An automated system of determining a surface interval between underwater dives, the system comprising: means for entering a first depth;means for entering a first time period corresponding to a bottom time associated with the first depth;means for entering a second depth;means for entering a second time period corresponding to a bottom time associated with the second depth;means for automatically computing a third time period corresponding to a surface interval using the first and second depths and the first and second time periods; andmeans for automatically displaying the third time period on a user readable display.

29. An automated system of determining a maximum depth in preparation for an underwater dive, the system comprising: means for entering a first time period;means for automatically determining and displaying a maximum depth using the first time period; andmeans for automatically displaying the maximum depth on a user readable display.

30. A method of automating an underwater dive table comprising: entering information relevant in planning an underwater dive;automatically determining at least one factor useful in planning a dive; andautomatically displaying the at least one factor on a user readable display.

31. The method of claim 30, wherein information comprises at least one of a depth; a bottom time period; a surface interval time period; and a pressure group.

32. The method of claim 30, wherein the at least one factor comprises at least one of a depth; a bottom time period; a surface interval time period; a pressure group; and a warning message.

33. A device for determining parameters useful in planning multiple underwater dives, the device comprising: a storage area configured to store information relevant in determining dive parameters;a user input configured to receive a first plurality of parameters relevant in planning multiple dives;a processor configured to determine a second plurality of dive parameters using the first plurality of dive parameters and at least a portion of the stored information; anda user readable display configured to display at least one of the second plurality of dive parameters.

34. The device of claim 33, wherein the first plurality of parameters comprises at least one of a pressure group, a depth, a surface interval time period, and an at depth time interval.

35. The device of claim 33, wherein the second plurality of parameters comprises at least one of a pressure group, a depth, a surface interval time period, and an at depth time interval.

36. A method for planning an underwater dive using a computing device, the method comprising: electronically storing information relevant in planning an underwater dive;entering a first plurality of parameters useful in planning multiple underwater dives onto an computing device;determining a second plurality of parameters useful in planning an underwater dive using the first plurality of parameters and at least a portion of the stored information;wherein the step of determining the second plurality of parameters is done by a processor; anddisplaying the second plurality of parameters on a user readable display.

37. The method of claim 36, further comprising electronically storing at least a portion of the first plurality of parameters.

38. The method of claim 36, further comprising electronically storing at least a portion of the second plurality of parameters.