Search results

You would think. Of course it depends on how familiar they are with your equipment. I did a boat dive and we were told to leave our BCD's in the front of the boat on the floor. The crew would then put the BCD's on the tanks. Once the tanks with our BCD's were placed in the racks we could put our...

You say you'll do whatever it takes to avoid surfacing with a SurGF of 99%. That's easy! Just set your GFHi to some percentage less than 99%. The Buhlmann algorithm with GF's is designed to calculate an NDL based on GFHi. That is, as long as you ascend with more than 0 minutes remaining of NDL...

What I wrote in the above quote in bold is not exactly true. Unfortunately, I was going by memory. When I ran my spreadsheet and put in a dive profile, the result was SurGF was increasing but at a slower rate than GF99. Both GF99 and SurGF are converging as the diver ascends. At the surface...

Don't you mean last diver to the bar loses. :cheers: What's this 30 stuff?

One legitimate scenario is if a student starts drifting up because either they're too light or they haven't released enough air from their BCD. It certainly would help instructors and their DM's if they could know whether the ascent is an equipment, skill, or a health problem. The first two...

For those of you who are wondering how to signal going to a shallower depth since the thumbs up signal in OW means going to the surface immediately, the NACD recommends raising an open palm toward the surface followed by the numerical signal for the new depth. The open palm signal without a new...

I read the article by DAN from the first post and came across this: "The proper course of action is for the buddy to return the signal, terminate the dive, and head to the surface together. Without a prearranged communication plan, however, buddies who don’t know what is wrong may spend...

In the 330 dives I've done I have never opened a tank valve all the way and then a 1/4 turn back, and I have never had a problem with the valves. I suspect the people who have a problem are using too much force against the seat of the valve and damaging it so a 1/4 turn back becomes a remedy for...

<deleted>

You know, after being a regular on SB for a number of years we seem to always have to define SAC. I wish we and the diving industry would change the acronyms to SACP for surface air consumption pressure and SACV for surface air consumption volume. RMV is not intuitive.

The m_value stands for maximum pressure. It should be understood as the maximum pressure difference between either itself and the surface pressure or between itself and ambient pressure. Since we need to keep the off gassing rate below a safe value it makes more sense to take the pressure...

I would like to offer some information that may help our understanding of GF99 and SurGF. This may be old information to those of you who have been using GF's. Here are the two equations used to calculate GF99 and SurGF (they may not be exactly the equations Shearwater uses but they serve here...

The Buhlmann ZHL-16C model uses 16 tissue compartments labeled 1 through 16; the fastest being 1 and the slowest 16. While the faster compartments on gas fast they also off gas fast. Compartments 1 and 2 generally clear on ascent. The slower compartments on and off gas the slowest. This suggests...

Multiple tissue compartments can offgass simultaneously. The controlling tissue compartment doesn't mean it is the only compartment to offgass but that it's calculated ceiling (yes, NDL dives have a ceiling) is the deepest or has the most positive ceiling. When I look at my spreadsheet that...

For me the solo cert gave me options. If I can't find a buddy I can still go diving. Solo is more relaxing in that I don't have to constantly look after a buddy. It gives me freedom in that I can do and go where I want when I want.

I updated the spreadsheet to include an automatic calculation of the air surface interval needed to get the controlling tissue compartment's current and surface gradient factor to 0. This might save some time for those of you who need to calculate this. This can be set for any profile when the...

Except for "managing their gas" recreational divers have been doing decompression stops for years. They just don't realize it. They're called safety stops. Physiologically, there's no difference between a mandatory deco stop and a voluntary safety stop. They both off gas the critical tissue(s)...

At the time I took PADI reliant (Sep 2013) using a twinset was acceptable. My regular buddy used one while I rented a 19 ft3 pony tank.

When I did my solo diving course (PADI self-reliant) I had to do gas planning and demonstrate it to the instructor. I was always a little bewildered by the necessity of this particular skill. Why is it so important to know as a solo diver and not for a (recreational) buddy pair? It could be that...

Yeah, you need to take a break. You contradicted yourself in the above quote! You first say there are no fundamental differences in the nature of dives. In the very next comment you say there is a fundamental difference in the nature of dives, and those differences are taken care of by the...