1|Page
PADI RDP Table & eRDPML Dive Planning Exam, PADI
Certification Program||Verified Exam!!||, 2026/2027 -
Question Test Bank with Verified Answers and
Rationales||Newest Exam!!!
A 60-minute tissue compartment requires _____________
to fill or empty completely, while a 120-minute
compartment requires _____________.
a. 1 hour/2 hours
b. 2 hours/4 hours
c. 6 hours/12 hours
d. 12 hours/24 hours - Answer-c. 6hours / 12 hours
A 60-minute tissue compartment requires 6 hours to fill or
empty completely, while a 120-minute compartment
requires 12 hours.
The term "half-time" is simply a way of representing what
is known as an "exponential relationship."
In our discussion of decompression theory it's used to
describe how quickly a tissue compartment will fill or
empty.
,2|Page
For example, a tissue compartment described as having a
"5-minute halftime" will fill (or empty) half of the total
amount of nitrogen it can hold in five minutes.
In five more minutes it will be 75% full; in five more
minutes 87.5%; in five more 93.6%; in five more 96.9%
and finally in six half-times (30 minutes total) the
compartment is considered full (or empty) at 98.4% of its
capacity (mathematically it never reaches 100%).
Therefore, a 60-minute tissue will completely fill or empty
in 6 hours (60 x 6 = 360 mins. or 6 hours).
A 120-minute tissue compartment will fill or empty in 12
hours (120 x 6 = 720 mins. or 12 hours).
The U.S. Navy selected the 120-minute tissue
compartment to control their "Surface Interval Credit
Table" because
a. they didn't know other compartments could be used.
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b. they were designing tables that enabled decompression
diving.
c. as most of their diving is surface air supplied, a different
decompression model had to be used.
d. this was the easiest way to account for individual
differences in physiology. - Answer-b. they were designing
tables that enabled decompression diving.
The U.S. Navy selected the 120-minute tissue
compartment to control their "Surface Interval Credit
Table" because they were designing tables that enabled
decompression diving. The primary function of the U.S.
Navy Tables was to enable safer decompression diving.
They also realized with the advent of scuba that provisions
were necessary for "repetitive diving." This required
consideration of how quickly the diver lost residual
nitrogen. To accommodate this the Navy developed a
"Surface Interval Credit Table." To avoid having to develop
several such tables to be used according to which tissue
compartment controlled the previous dive, they chose an
easier approach — develop only one table based on a
single compartment. Determining which compartment to
use was simple. As their tables would provide for
, 4|Page
decompression diving — even repetitive decompression
dives — they had to use the slowest tissue compartment
in their model; one which would come into play only during
decompression dives. That compartment was the 120-
minute compartment, which requires 12 hours to fully in or
out gas. This explains why it takes up to 12 hours to fully
out-gas when using the U.S. Navy Tables.
The Recreational Dive Planner uses a 60-minute tissue
compartment to control its "Surface Interval Credit Table"
because
a. there are no safety factors built into its design.
b. the decompression stops are shorter than the Navy
Tables.
c. it is a better way to account for individual differences in
physiology.
d. if divers don't exceed the NDLs the slow 120-minute
compartment can be virtually ignored. - Answer-d. if divers
PADI RDP Table & eRDPML Dive Planning Exam, PADI
Certification Program||Verified Exam!!||, 2026/2027 -
Question Test Bank with Verified Answers and
Rationales||Newest Exam!!!
A 60-minute tissue compartment requires _____________
to fill or empty completely, while a 120-minute
compartment requires _____________.
a. 1 hour/2 hours
b. 2 hours/4 hours
c. 6 hours/12 hours
d. 12 hours/24 hours - Answer-c. 6hours / 12 hours
A 60-minute tissue compartment requires 6 hours to fill or
empty completely, while a 120-minute compartment
requires 12 hours.
The term "half-time" is simply a way of representing what
is known as an "exponential relationship."
In our discussion of decompression theory it's used to
describe how quickly a tissue compartment will fill or
empty.
,2|Page
For example, a tissue compartment described as having a
"5-minute halftime" will fill (or empty) half of the total
amount of nitrogen it can hold in five minutes.
In five more minutes it will be 75% full; in five more
minutes 87.5%; in five more 93.6%; in five more 96.9%
and finally in six half-times (30 minutes total) the
compartment is considered full (or empty) at 98.4% of its
capacity (mathematically it never reaches 100%).
Therefore, a 60-minute tissue will completely fill or empty
in 6 hours (60 x 6 = 360 mins. or 6 hours).
A 120-minute tissue compartment will fill or empty in 12
hours (120 x 6 = 720 mins. or 12 hours).
The U.S. Navy selected the 120-minute tissue
compartment to control their "Surface Interval Credit
Table" because
a. they didn't know other compartments could be used.
,3|Page
b. they were designing tables that enabled decompression
diving.
c. as most of their diving is surface air supplied, a different
decompression model had to be used.
d. this was the easiest way to account for individual
differences in physiology. - Answer-b. they were designing
tables that enabled decompression diving.
The U.S. Navy selected the 120-minute tissue
compartment to control their "Surface Interval Credit
Table" because they were designing tables that enabled
decompression diving. The primary function of the U.S.
Navy Tables was to enable safer decompression diving.
They also realized with the advent of scuba that provisions
were necessary for "repetitive diving." This required
consideration of how quickly the diver lost residual
nitrogen. To accommodate this the Navy developed a
"Surface Interval Credit Table." To avoid having to develop
several such tables to be used according to which tissue
compartment controlled the previous dive, they chose an
easier approach — develop only one table based on a
single compartment. Determining which compartment to
use was simple. As their tables would provide for
, 4|Page
decompression diving — even repetitive decompression
dives — they had to use the slowest tissue compartment
in their model; one which would come into play only during
decompression dives. That compartment was the 120-
minute compartment, which requires 12 hours to fully in or
out gas. This explains why it takes up to 12 hours to fully
out-gas when using the U.S. Navy Tables.
The Recreational Dive Planner uses a 60-minute tissue
compartment to control its "Surface Interval Credit Table"
because
a. there are no safety factors built into its design.
b. the decompression stops are shorter than the Navy
Tables.
c. it is a better way to account for individual differences in
physiology.
d. if divers don't exceed the NDLs the slow 120-minute
compartment can be virtually ignored. - Answer-d. if divers
