General Rules for Using the eRDPML

The following rules apply to using the eRDPML and RDP Table. The eRDPML will prompt you to recall some of these rules by displaying a message and emitting 3 short beeps if sound is on. Note that you can turn off the beeps by deactivating sound. For your convenience, these rules appear inside the eRDPML’s flip cover. You’ll learn more about these rules and when they apply.

  1. The Recreational Dive Planner is designed specifically for planning recreational (no decompression) dives on air only. Do not attempt to use it for planning decompression dives or dives using breathing gases other than air.

  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. A safety stop is recommended at the end of all dives whenever possible, regardless of depth or duration. The eRDPML provides prompts for this rule, however, ALL General Rules apply when using the eRDPML.

  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 multiday dive series.

  7. Ascend from all dives at a rate not to exceed 18 metres/60 feet per minute. Slower is acceptable and encouraged. Be a S.A.F.E. Diver — Slowly Ascend From Every Dive.

  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. Avoid following a dive with a deeper dive. Always plan your deepest dive first.

  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 feet must be followed by a surface interval of at least 6 hours.

  11. When the eRDPML reads “NEW DIVE” and “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 minimum surface intervals when making more than 3 dives in a day still apply.