Multi Level Diver course ??????

[pdhenry]

IIRC there was one multi-level dive question on my Nitrox exam, involving calculation of Oxygen exposure from a multilevel dive. The answer accepted as correct was to calculate as it two dives with no SI.

 

[tursiops]

IIRC there was one multi-level dive question on my Nitrox exam, involving calculation of Oxygen exposure from a multilevel dive. The answer accepted as correct was to calculate as it two dives with no SI.

That is for O2 exposure, not N2 uptake.

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[Basking Ridge Diver]

So you're given a dive briefing on let's say a wreck. You know the different "levels" on the wreck. But you really don't know how much time you want to spend at each level (my shell collecting comes to mind). Or you may just go to the bottom, spend a few minutes there and gradually ascend (like a wall dive). How do you plan that?-- other than following your computer and maybe using the RDP to plan a square profile and go from there. As I have mentioned in the past, the eRDPml would seem quite useless as would the Wheel.

I generally don't wait until I am sitting on the boat to do my dive plan. I create a plan after I am setting up the dive - with known location and depths. Do I plan every dive I do - no... But if I am going deeper than 50 feet I generally use an excel sheet that I built that tracks Depth, Time and my RMV/SAC rate. I use the information as a guide in a square profile or multi-profile just to make sure I have enough gas for what I think I am going to do.
Do you need to Plan your Dive and Dive your Plan - no but it may help you frame your dive. I generally use a liberal RMV/SAC for the plan and watch my SPG and PDC as a confirmation and if I have extra gas - I use it as I want and extend the dive as needed or head on up based on conditions.

 

[Remy B.]

Honestly I use the DC to tell me or watch it before it beep,s, but most of my dives had been around 27m, only once hit the 39.6 for a short time, and the 37.4m for around 7min probably, but the descent on that dive was very fast so I had enough time for the NDL

I do like class rooms but it seems to me that this coourse is kind of pointless if I have my own DC, it looks more like "Put Another Dollar In" type course, better to spend that dollar in Deep Diver course or Wreck that are the ones I do like more and I believe it will bring more knowledge to me.

 

[TMHeimer]

I generally don't wait until I am sitting on the boat to do my dive plan. I create a plan after I am setting up the dive - with known location and depths. Do I plan every dive I do - no... But if I am going deeper than 50 feet I generally use an excel sheet that I built that tracks Depth, Time and my RMV/SAC rate. I use the information as a guide in a square profile or multi-profile just to make sure I have enough gas for what I think I am going to do.
Do you need to Plan your Dive and Dive your Plan - no but it may help you frame your dive. I generally use a liberal RMV/SAC for the plan and watch my SPG and PDC as a confirmation and if I have extra gas - I use it as I want and extend the dive as needed or head on up based on conditions.

Your planning seems thorough. I don't use an excell sheet or anything complicated (well, complicated for me...), but pretty much get an approximation of what I want to do, which seems to be what you do. I'm unsure when exactly you do the planning--You said you don't wait until you're on the boat but you plan it after you're setting up the dive with known locations & depths. So you get the info. before the boat leaves the dock/shop, I assume? Some of the boats I've been on have changed plans en route to sites, but, anyway.

At any rate, one still has to have a pretty good idea of how long one will be at whatever depth. If not, I check my computer for remaining bottom time, my analog SPG for remaining gas and my watch to compare with a square profile. For a dive to 80' I generally figure 20 mins. down there then start up, since it's 30 mins. NDL, so there's plenty of time to spare. If I'm not near the bottom for a fair bit of time that's when I pay more attention to the computer. Then again, my dives are usually pretty simple.

 

[TONY CHANEY]

Dang, am I the only diver that has actually done the course? Well, I did not have a DC at the time and I wanted to extend bottom time which the square profile would not allow. So I took the course and had a blast doing lots of dives and I used the wheel far more than I ever did the dive tables. So as a DM / MSD I would assist the Instructor with teaching others Multiple level dives with Nitrox. Very happy times by all! But there are situations where it is great and others situations where you cannot use it. I was stationed in Okinawa, Japan where we had walls, lots of walls. Perfect for MLD planning. Now with shore entry dives, rivers, caves and shallow dives it does not change much and I will not even break out the wheel for these. I still break it out every now and then but just to check it out. The dive computer has changed almost everything and it is getting harder to teach any table work to new divers seeking advanced dive training...most I have met have never mastered the basic table stuff. I am not a down in the mouth diver talking about the way it use to be back in the days but simply stating facts. Form what I have seen it would be better for a lot of divers to actually read the computer instructions. I find it very useful to know that the computer is based on.

 

[Basking Ridge Diver]

I'm unsure when exactly you do the planning--You said you don't wait until you're on the boat but you plan it after you're setting up the dive with known locations & depths. So you get the info. before the boat leaves the dock/shop, I assume? Some of the boats I've been on have changed plans en route to sites, but, anyway.

I try to do my plan when I figure out the dive location - but I agreed with your approach as well - most of the boats I dive stay in the same depth range plus or minus 10 feet. Much more than that and I would use my PDC and SPG to dive. All I was getting at is I do the initial plan of what time, depth and RMV/SAC I may expect so I have something to compare my actual against. If the location and depth change I have a feel for the depth and time - then it is up to me. My gauges are like the rear view mirrors in my car - I am always aware of my surroundings and checking but not staring into them. Relaxing and doing the dive - especially in a new area or new conditions are the unknowns but having a plan make me feel like I am in control (I know... but it helps me).

 

[Goodtime Adventures]

To be fair most dives are multilevel dives. I don't know many divers who would do/need to do a 'square' profiled dive as per the PADI RDP tables. Although the tables suffice perfectly well for entry level, once you get on to more advanced (ie deeper) level, dive plans that are perfectly safe and allowable with a dive computer or multi level dive planner (the PADI RDPML, which replaced the wheel) are not permissible with the standard RDP because of all the rounding in terms of depth and bottom time. This is what the Multilevel specialty is designed to teach you - how to safely plan and execute dives using more advanced planning tools. For the record, since NetDoc already mentioned it, I really miss the wheel. It could be a pain to explain and teach, but I quite liked it.

In terms of the course itself, as is often the case, what you get out of it depends on the instructor teaching it. For most divers who have their own personal computer, they should be able to plan and execute multilevel dives already - as long as they have a sound appreciation of the rules for using a computer, and how theirs actually works. However the number of times I've seen divers buy a computer and happily take it off on a trip without reading up on the instruction manual or checking out the functions properly beggars belief. If I had a dollar for every time I'd been asked what this symbol means and what that beep was for etc etc Well suffice to say I'd be happily retired and living the good life somewhere with mojito in hand right about now....

 

[Remy B.]

To be fair most dives are multilevel dives.

In terms of the course itself, as is often the case, what you get out of it depends on the instructor teaching it. For most divers who have their own personal computer, they should be able to plan and execute multilevel dives already - as long as they have a sound appreciation of the rules for using a computer, and how theirs actually works.

What rules you refer to ?

Been a rucky, I got a entri level DC so it tell me if I'm ascending to fast, and NDL, too feel more safe, since I like to enjoy my dive and spend as much time as possible down there without getting in throuble, and not be in a position to re-calculate or get the calculations wrong at dept in case something unespected happen, I did read the manual and understand what it does, but didn't know there were rules to use a DC.

But I will say I need and will use my dive tables more and plan my dives and not ride my computer in case my DC take a dump in middle of my dive and apply the "what if"

So all know I'm very new to diving and all the times I have been using SCUBA it was next to an instructor, I'm planning to dive without supervision eventually, there is where I will/need to start my dive planning, and take a look at the tables and not only rely on my DC.

 

[Goodtime Adventures]

Nothing groundbreaking or unexpected, and nothing you should not have been told by your instructor when first introduced to computers. The main ones are:

Never share a DC between buddies or buddy teams (bit of a no brainer really)
Use the most conservative computer for NDL's, safety stops etc (again, not rocket science)
Do not exceed limits of the computer (ditto)
Adhere to manufacturers recommendations re usage and care (ditto)

Again, you'd think this would all be common sense, but experience has taught me otherwise on a few occasions!