PADI Recreational Dive Planner (RDP) 4 — Questions and Answers
Question 1: A diver surfaces from a first dive as pressure group 'P'. According to the RDP, what does this suggest?
- The diver had a perfect dive with no nitrogen loading
- The diver is at or very near the no-decompression limit and carries a high level of residual nitrogen (Correct answer)
- The diver needs to descend again immediately
- Pressure group P is not found on the RDP
Correct answer: The diver is at or very near the no-decompression limit and carries a high level of residual nitrogen
Pressure group P is close to the maximum letter on the RDP, indicating a high level of residual nitrogen near the NDL.
Question 2: What is the recommended ascent rate according to PADI when using the RDP?
- 60 feet (18 m) per minute
- 30 feet (9 m) per minute or slower (Correct answer)
- 100 feet (30 m) per minute
- Ascent rate does not matter if NDLs are followed
Correct answer: 30 feet (9 m) per minute or slower
PADI recommends ascending at 30 feet (9 meters) per minute or slower to allow safe nitrogen elimination.
Question 3: Which of the following activities should a diver AVOID after a dive to prevent increasing DCS risk, according to PADI RDP guidelines?
- Drinking water
- Flying or traveling to altitude before sufficient off-gassing (Correct answer)
- Eating a light meal
- Reviewing their dive log
Correct answer: Flying or traveling to altitude before sufficient off-gassing
Flying or ascending to altitude after diving reduces ambient pressure, causing residual nitrogen to expand and potentially cause DCS.
Question 4: When using the RDP eRDPml (multi-level version), what is the primary advantage over the table version?
- It allows decompression dives
- It accounts for actual depth changes during a dive, giving credit for time spent at shallower depths (Correct answer)
- It eliminates the need for a surface interval
- It can be used at altitudes above 10,000 feet without modification
Correct answer: It accounts for actual depth changes during a dive, giving credit for time spent at shallower depths
The eRDPml calculates nitrogen loading level by level, giving credit for time at shallower depths rather than assuming the entire dive at the deepest point.
Question 5: A diver surfaces as pressure group 'G' and wants to return to pressure group 'C' before the next dive. How would they find the required surface interval?
- Table 1 — find where G and C intersect
- Table 2 — find row G and look across to column C to read the surface interval (Correct answer)
- Table 3 — find G and subtract C
- The RDP does not allow selecting a target pressure group
Correct answer: Table 2 — find row G and look across to column C to read the surface interval
Table 2 is the Surface Interval Credit Table; find your starting group on the left and scan across to your desired end group to read the required surface interval.
Question 6: According to PADI, after how many hours should a diver wait before flying after a single recreational no-decompression dive?
- At least 6 hours
- At least 12 hours (Correct answer)
- At least 24 hours
- At least 48 hours
Correct answer: At least 12 hours
PADI recommends a minimum pre-flight surface interval of 12 hours after a single no-decompression dive.
Question 7: What is the purpose of the 'pressure group' letters (A through Z) on the RDP?
- To rank divers by certification level
- To represent how much residual nitrogen a diver has in their body after a dive (Correct answer)
- To indicate the number of dives completed in a day
- To show the diver's depth rating
Correct answer: To represent how much residual nitrogen a diver has in their body after a dive
Pressure group letters are a shorthand code for the amount of residual nitrogen dissolved in a diver's tissues after a dive.
PADI Recreational Dive Planner (RDP) 4
A diver surfaces from a first dive as pressure group 'P'.
According to the RDP, what does this suggest?