How to use The Wheel
- Thread starter tomcat
- 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
The Chairman
Chairman of the Board
accompaning the wheel worked for me. I found it quite suspicious that I have known no PADI Master Instructors that were really comfortable with it's use. I think it's inclusion in the DM course will be terminated shortly. I was the first DM cndidate for my DI that had answered all of the wheel questions correctly. PADI also sells a video that might be helpful.
davidofaustin
Contributor
Started to write several reasons that the Wheel manages to stick around, but it boils down to the fact that its the easiest, least expensive way to increase your bottom time in a safe manner.
I like the wheel, the manual that comes with it is quite good, and if you will go through it, step by step from cover to cover, you will be quite good with it.
I still use it for "special cases" when diving with new open water divers, and give introductory instruction - when I do use it.
I also use it with my computer to verify and graph out, multi-level dives, with my non computer diving buddies.
Big thumbs up on the Wheel, from me...
Dave
I like the wheel, the manual that comes with it is quite good, and if you will go through it, step by step from cover to cover, you will be quite good with it.
I still use it for "special cases" when diving with new open water divers, and give introductory instruction - when I do use it.
I also use it with my computer to verify and graph out, multi-level dives, with my non computer diving buddies.
Big thumbs up on the Wheel, from me...Dave
thanks guys. so i guess there aren't any ready resources online where i can preview what this wheel thing is all about.
i recently started training for DM and found out that it was a requirement to have a wheel. seems like another thing to have to buy since i already have a table and use a dive com. oh well, u won't catch me spinning it around too often!
i recently started training for DM and found out that it was a requirement to have a wheel. seems like another thing to have to buy since i already have a table and use a dive com. oh well, u won't catch me spinning it around too often!
trymixdiver
Guest
i have mine in the trash as we speak, i was going to throw it out. No need for them for my type of diving. if your local your welcome to them
Andy
Andy
DameDykker
Guest
I've seen the weel demonstrated - and I wasn't impressed. It was also rusted and didn't spin non to well. I'll recommend the DCIEM tabel. Only one slate, very easy to use, no moving parts, includes multilevel, surface intervals and altitude diving as well as some decompression. And .. :$: saved. It olny cost about 1/6 of the weel.
Pia
Pia
I too "had" to learn the wheel for the PADI DM. lucky for me, one friend had the video which was a great help. Better yet, another friend who was a work colleague at the time, spent a number of noon hours going through examples until I could understand how to do the PG and SI determinations upside down and backwards.... With their help I aced the exam.
If I can help, ask away.
If I can help, ask away.
kkoski
Registered
I've found the wheel to be expensive & not necessary. I know PADI requires their dive masters to have and be able to use a wheel, I think it's just more money in their pocket. A normal dive table can be used to calculate multi level dives (or estimate them for computer users). Here's how: (All worked on PADI Recreational Dive Planner)
First, note that going across Table 1 horizontally gives different times at different depths for a given letter group. E.G. 27 minutes at 40' is the same as 17 minutes at 60' is the same as 13 minutes at 80', after all of these dives you will be an E.
Problem 1
Dive 1: 15 min at 80 feet, 25 min at 40 feet. (Your last dive was more than 24 hours ago).
Use Table 1
15 minutes at 80' makes you a G, reading over to the left, staying in the G row, this dive is equivalent to 34 minutes at 40'. You want to dive 25 min at 40'. You can represent the total multi-level dive as (34 min + 25 min)= 59 min at 40', making you a N.
Surface Interval: 1:45
From Table 2, a N with a SI of 1:45 becomes a B.
Dive 2: 15 min at 70', 24 min at 50' As long as possible at 35'.
First we'll calculate the Residual Nitrogen Time at 70' using Table 3 (Repetitive Dive Timetable). A diver who is a B has a RNT of 9 minutes at 70'.
This makes the Total Bottom Time 15+9=24 minutes at 70' making (from Table 1) the diver a K. This dive is equivalent to (reading across the K row to the left to the 50' column) a 36 minute dive at 50'. So we can think of the total bottom time, up to the end of the 24 min at 50' as a 36+24=60 minute dive at 50' (The 60 minutes takes into account the RNT from dive 1, the time spent at 70' on dive 2, and the time spent at 50' from dive 2). A dive of 60 min at 50' makes the diver a S. Reading across to the time at 35' required to make a S diver we get 108 minutes.
The No-Decompression limit at 35' is 205 minutes. This means the diver can spend 205-108=97 minutes at 35' and come out of the water a Z.
If the diver spent 60 minutes at 35', they would come out a X.
End Problem 1
I know this seems complicated, but if you work it with your table it really isn't. It also gives a very good intuitive understanding of the table.
Problem 2
Dive 1: 15 minutes at 100', 30 min at 50'
Surface interval: 1:00
Dive 2: 20 minutes at 50', 30 minutes at 30'
Answers
The diver is a T after Dive 1.
The diver is a G after SI.
The diver is a T after Dive 2.
End Problem 2
-Katrina
katrina@koski.net
Disclaimer
To quote my wise mother "You wouldn't jump off a bridge if they told you to", make sure you believe this works, don't trust me. Verify with a table and wheel to convince yourself you get the same results. (You can sneak a peak of the wheel at your LDS so you don't have to buy one).
First, note that going across Table 1 horizontally gives different times at different depths for a given letter group. E.G. 27 minutes at 40' is the same as 17 minutes at 60' is the same as 13 minutes at 80', after all of these dives you will be an E.
Problem 1
Dive 1: 15 min at 80 feet, 25 min at 40 feet. (Your last dive was more than 24 hours ago).
Use Table 1
15 minutes at 80' makes you a G, reading over to the left, staying in the G row, this dive is equivalent to 34 minutes at 40'. You want to dive 25 min at 40'. You can represent the total multi-level dive as (34 min + 25 min)= 59 min at 40', making you a N.
Surface Interval: 1:45
From Table 2, a N with a SI of 1:45 becomes a B.
Dive 2: 15 min at 70', 24 min at 50' As long as possible at 35'.
First we'll calculate the Residual Nitrogen Time at 70' using Table 3 (Repetitive Dive Timetable). A diver who is a B has a RNT of 9 minutes at 70'.
This makes the Total Bottom Time 15+9=24 minutes at 70' making (from Table 1) the diver a K. This dive is equivalent to (reading across the K row to the left to the 50' column) a 36 minute dive at 50'. So we can think of the total bottom time, up to the end of the 24 min at 50' as a 36+24=60 minute dive at 50' (The 60 minutes takes into account the RNT from dive 1, the time spent at 70' on dive 2, and the time spent at 50' from dive 2). A dive of 60 min at 50' makes the diver a S. Reading across to the time at 35' required to make a S diver we get 108 minutes.
The No-Decompression limit at 35' is 205 minutes. This means the diver can spend 205-108=97 minutes at 35' and come out of the water a Z.
If the diver spent 60 minutes at 35', they would come out a X.
End Problem 1
I know this seems complicated, but if you work it with your table it really isn't. It also gives a very good intuitive understanding of the table.
Problem 2
Dive 1: 15 minutes at 100', 30 min at 50'
Surface interval: 1:00
Dive 2: 20 minutes at 50', 30 minutes at 30'
Answers
The diver is a T after Dive 1.
The diver is a G after SI.
The diver is a T after Dive 2.
End Problem 2
-Katrina
katrina@koski.net
Disclaimer
To quote my wise mother "You wouldn't jump off a bridge if they told you to", make sure you believe this works, don't trust me. Verify with a table and wheel to convince yourself you get the same results. (You can sneak a peak of the wheel at your LDS so you don't have to buy one).
Rooster1
Guest
Don't you just spin the wheel and pic a letter Hehehehehe
Similar threads
