UTD Essentials of Recreational Diving - What graduates say

[RainPilot]

To reduce narcosis. Best practice seems to be to limit END to 30m. Obviously that's not a "you're gonna die!!" thing but generally cave and tech divers try to follow that where feasible.

The tenets of UTD include things being scalable. Why teach a tech diver that it's a good idea to put squeak in his tank for deeper than 30m but not allow a rec diver to do the same?

Note, none of this is prescriptive. You are trained to use an additional tool, it's up to you as the thinking diver to decide on the appropriate tools.

You could do a UTD course in a back inflate BCD if it won't endanger your team and you have a compelling reason to use it. I would have no problem training a student with a back issue on a suitable BCD. Or modifying a BP/W harness to allow load bearing ala Transpac etc.

 

[wetb4igetinthewater]

To improve clarity and help with decision making. I think it's a good idea.

Hmm, okay, for dives shallower than 100 feet, it isn't worth my dime, but each person needs to make that decision for himself/herself.

 

[RainPilot]

Nobody dives He shallower than 100'. Deeper than that and it's going to depend on conditions, workload, experience and, unfortunately, cash flow.

The helitrox comes in on Rec 3 which is basically an amalgam of PADI Rescue, Deep speciality and a bit of the old NAUI Master Scuba Diver course.

 

[RainPilot]

These aren't heavy on the balloon stuffing.

Standard gas for Rec 3 is 25/25, gives a PPO2 of average 1.2 and a END of 100 at 130. At a 100$ for 220 cf that's around...too tired to do the maths. Maybe 5-10$ plus whatever a half tank of 32% cost you?

For cold low vis diving below 100' I wouldn't think twice. For toasty clear waters here? Hmmmm.

 

[CAPTAIN SINBAD]

Color me ignorant! Does this use tables or PDCs???

Here is what it looks like:

Had to be followed with this:

The above is what it used to look like before Ratio Deco 2.0 came about. I would assume the first stop would be at 66 feet instead of 75 for a dive to 100?

 

[The Chairman]

Interesting. These tables were based on what?

I know that PADI & NAUI are modified Navy tables with a significant amount of buffers built in. These are reminiscent of Weinke tables, but they appear to be oversimplified even for them. What's the difference between these and RD?

 

[The Chairman]

​

Ah, now I recognise this as a modified rule of 120/140. It kind of slides between air (120) and 32 (140). Are these used with depth averaging?

For those who don't know, a quick way to check your dive plan against reality is to use the rule of 120/140. Subtract the depth from 120 for air and 140 for NitrOx and you have a gross approximation of what your NDL should be. For a dive to a depth of 60 ft

120-60 = 60 min on air
140-60 = 80 min on NitrOx

These were never meant to replace tables or a PDC and they don't rely on depth averaging. I also recommend a full five-minute safety stop in any event.

 

[wetb4igetinthewater]

​

Ah, now I recognise this as a modified rule of 120/140. It kind of slides between air (120) and 32 (140). Are these used with depth averaging?

For those who don't know, a quick way to check your dive plan against reality is to use the rule of 120/140. Subtract the depth from 120 for air and 140 for NitrOx and you have a gross approximation of what your NDL should be. For a dive to a depth of 60 ft

120-60 = 60 min on air
140-60 = 80 min on NitrOx

These were never meant to replace tables or a PDC and they don't rely on depth averaging. I also recommend a full five-minute safety stop in any event.

I never heard that before. Interesting

 

[RainPilot]

For a 100' dive on nitrox they give you 30 min so a lot more conservative than the 120/140 rule. They also work on max depth unless there is a major difference i.e. a bounce down for 5 min then the bulk of the dive at a much shallower depth, in which case average depth can be used.

 

[randytay]

Hmm, okay, for dives shallower than 100 feet, it isn't worth my dime, but each person needs to make that decision for himself/herself.

​

Ah, now I recognise this as a modified rule of 120/140. It kind of slides between air (120) and 32 (140). Are these used with depth averaging?

For those who don't know, a quick way to check your dive plan against reality is to use the rule of 120/140. Subtract the depth from 120 for air and 140 for NitrOx and you have a gross approximation of what your NDL should be. For a dive to a depth of 60 ft

120-60 = 60 min on air
140-60 = 80 min on NitrOx

These were never meant to replace tables or a PDC and they don't rely on depth averaging. I also recommend a full five-minute safety stop in any event.

Actually it is more conservative than 120/140. Remember this is on 32. On Air, subtract 10 minutes at each depth.