SentinelAce
Contributor
I need to do some practice examples for the dive master. I have googled and can't find any. I was hoping I could do some then check my answers. Any advice?
Practice Dive Plan tables ?
- Thread starter SentinelAce
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Dive 1. 60ft for 40 minutes
Surface intervel 40 minutes
Dive 2. ??? Ft for 50 minutes
Dive 1. 60ft for 40 minutes
Surface intervel ??? minutes
Dive 2. 30 Ft for 50 minutes
Dive 1. 60ft for 40 minutes
Surface intervel 40 minutes
Dive 2. 30 Ft for 50 minutes
Surface intervel 40 minutes
Dive 3. 30 ft for 50 minutes
What's the total dive time following the rules including safety stops?
There's a couple off the top of my head. Those kind of things? I'll make some more if you'd like.
Also feel free to make up your dive plans and post it up. I'd look them over.
Cameron
Surface intervel 40 minutes
Dive 2. ??? Ft for 50 minutes
Dive 1. 60ft for 40 minutes
Surface intervel ??? minutes
Dive 2. 30 Ft for 50 minutes
Dive 1. 60ft for 40 minutes
Surface intervel 40 minutes
Dive 2. 30 Ft for 50 minutes
Surface intervel 40 minutes
Dive 3. 30 ft for 50 minutes
What's the total dive time following the rules including safety stops?
There's a couple off the top of my head. Those kind of things? I'll make some more if you'd like.
Also feel free to make up your dive plans and post it up. I'd look them over.
Cameron
OP
SentinelAce
Contributor
wow thanks man. I'll work on this tomorrow
OP
SentinelAce
Contributor
I did the first two. About to get on a boat so let me know if I did this right lol.
The first dive, I will be in pressure group Q with a surface interval for 40 min. The second pressure group would be I putting my max depth at 40'.
The second dive, I will be in pressure group Q. Since I want to be at that depth for 50 minutes my pressure group would be W. W does not intersect with Q so the surface interval would be 0
The first dive, I will be in pressure group Q with a surface interval for 40 min. The second pressure group would be I putting my max depth at 40'.
The second dive, I will be in pressure group Q. Since I want to be at that depth for 50 minutes my pressure group would be W. W does not intersect with Q so the surface interval would be 0
Your answer to the second question above is correct based on the PADI dive table...NAUI states a Surface Interval must be a minimum of 10 minutes between dives and that the diver must consider the 2nd dive as a continuation of the first dive if the surface interval is less than 10 minutes long.
Some computers (Suunto in particular), if you attain the surface and re-descend within 5 minutes the computer will continue counting the dive time as a continuation of the previous dive instead of as a 2nd dive.
NAUI further recommends a minimum of 1-hour surface interval between dives.
The US Navy Dive Manual also recommends a minimum surface interval of 10 minutes between dives:
"9-9.1 Repetitive Dive Procedure. To use the repetitive dive procedure described below,
the interval on the surface between dives must be at least 10 minutes. If the surface
interval between dives is less than 10 minutes, add the bottom time of the two
dives and enter the decompression table at the deeper of the two depths."
The minimum surface interval displayed on the NAUI dive table is 10min while the PADI table shows a minimum of 0-2min. I can't find any reference for a PADI recommended minimal surface interval time except what the RDP table calculates.
-Z
You'll need to revise BOTH (if PADI) ERDPML and Tables. I know when I took DM the only real question I had when starting post E learning was "WTF is the ERDPml?" having never seen one when I started diving.
@Bubble Junky has some nice training videos on his site for all dive theory
PADI ERDPml PADI RDP Tables which I highly recommend (I have no connection to the centre), I used them and still do to refresh my memory, and will be re-studying in depth over Christmas in readiness for my IDC Staff exams.
A couple tips.
There will be a couple of questions where two answers will be very close (so you can't guess) Also remember the rules set out on the RDP - actually you don't need to remember them because the answers are there on your RDP - just remember that they are there.
If you get the question where you calculate dive time and SI over multiple dives, remember the SS requirements as set out on the RDP - not the generally recommended of 3min SS each dive.
Please let me know if my response to the 3rd dive scenario is correct.
-Z
Coming out of the 1st dive the diver will be in pressure group Q...after 40min SIT they are in group I, a 30ft dive for 50 min with an RNT of 48 gives a TBT of 98 so the diver would come out of the water at pressure gorup R....after the next 40min SIT they would be in pressure group J with 52 min of RNT another 50 min would give a TBT of 102 so ending pressure group would be S.
Total dive time would be 140min as there is no required safety stop...if the diver elects to do a 3min safety stop at the end of each dive then total dive time would be 149 min.
I am not a PADI trained diver so I am unsure if one would even count the safety stops in the total dive time as PADI calculates bottom time from the moment the diver descends to the moment the diver starts their ascent to the surface. The above total dive time does not take into consideration time to ascend which for PADI is 60ft/min...if ascent time is taken into consideration along with safety stops then there would be an additional 2 minutes added in (60 second ascent time for first dive and 30 seconds for each of the second and third) which brings the total dive time to 151 minutes.
Total dive time would be 140min as there is no required safety stop...if the diver elects to do a 3min safety stop at the end of each dive then total dive time would be 149 min.
I am not a PADI trained diver so I am unsure if one would even count the safety stops in the total dive time as PADI calculates bottom time from the moment the diver descends to the moment the diver starts their ascent to the surface. The above total dive time does not take into consideration time to ascend which for PADI is 60ft/min...if ascent time is taken into consideration along with safety stops then there would be an additional 2 minutes added in (60 second ascent time for first dive and 30 seconds for each of the second and third) which brings the total dive time to 151 minutes.
-Z
The NAUI tables repeat the Navy tables. The PADI tables are very different from them and are based on extensive independent research supervised by Dr. Spencer. The surface intervals are the primary reason--even the impetus--for the difference.
The Navy tables that were guiding pretty much all recreational diving during the early years of American scuba created the 120 minute compartment and made that the theoretical tissue controlling the surface interval. That leads to very long surface intervals. Navy divers usually do one dive a day, and it can be long, so having long surface intervals is not a big deal. For recreational diving operations, it is a very big deal. You don't want divers sitting on a boat any longer than necessary between dives.
PADI's research led them to conclude that the 120 minute compartment was much longer than necessary for the nearly all recreational dives, and the for vast majority, the 40 minute compartment was just fine. They elected, however, to go with the 60 minute compartment for the tables they were creating. They also shortened the NDLs for the first dive, and they nearly doubled the number of pressure groups in order to cut down on the amount of rounding necessary. Recreational divers who stayed within those limits could thus get back into the water for a second or third dive much, much sooner than divers using the Navy tables.
Today, pretty much all computers use an algorithm that is pretty consistent with the PADI tables in terms of surface intervals, and this allows dive operations to run the schedules they do. This creates something of a problem that I have noted in past discussions. A few people on SB have said they were trained to use the Navy tables (or NAUI or SSI) and still use them to an extent--that is, they don't actually look at the tables but instead just remember the first dve NDLs and use them to guide all their dives. That means they really aren't following the tables, because they are treating second dives as if they are first dives. Not only that, they are getting into the water for that second dive when everyone else does--meaning they are having about half the surface interval they are supposed to have for a second dive, which compounds the problem.
OP
SentinelAce
Contributor
Not to be annoying, but can my thread not get hijacked? I did forget to specify this is PADI. Thanks guys
Similar threads
