r/scuba

So based on the information currently available, this would not be a recreational dive by any standard — it would effectively be a full technical decompression cave dive.

A cave penetration beginning around 55 m, extending roughly 150 m in length, with the divers ultimately found around 60 m inside the cave, already places the dive far beyond the limits of recreational training and equipment configuration.

To conduct a dive like this safely, you would normally require doubles or a CCR simply to carry enough gas for the bottom phase, the decompression obligation, and adequate emergency reserves. Additional stage cylinders with dedicated decompression gases would also typically be required. We are potentially talking about a 2–3 hour dive involving extensive planning, contingency procedures, and staged deco/hang tanks in case of a gas emergency.

And that is before considering the cave environment itself.

Technical cave diving at these depths requires guidelines, cookies, redundant lights, specialized cave equipment, and — most importantly — advanced cave and decompression training with substantial real-world experience. Not basic cavern training or recreational overhead-environment exposure, but full technical cave certification and proper operational discipline.

If the reports are accurate that the divers were using rental recreational equipment, single AL80 cylinders, and air, it becomes extremely difficult to understand how this dive could have been considered feasible from a gas-planning perspective alone.

At 60 m, the NDL is only a matter of few minutes (~5 to 8). Even an immediate turn at depth would still result in a significant controlled ascent (13 min according to UTD recreational Ascent Profile), and the rock bottom requirement for two divers sharing gas at that depth is already above 200 bar. The Gas needed for one diver to descend to 60m, stay at depth for 5 min and return the dive would be close to 160-200 bars (based on 20-25 sac rate and a 13 min controlled ascent) excluding any sort of emergency or problem solving.

A single AL80 simply does not provide enough gas to safely descend to 55–60 m, stay the NDL and ascend.

Let alone penetrate a cave, and return while maintaining an adequate reserve for a gas-sharing emergency. Even without an emergency and without the cave penetration; the available gas margin would be extraordinarily small once depth, stress, elevated SAC rates, ascent time, and potential decompression (in case of NDL breach) are factored in. And we don’t even account for the inadequacy of Air as a Gas for any depth below 30m and the narcosis consequences  

From a diving standpoint, the reported configuration and profile are fundamentally incompatible with accepted safety margins for this type of dive.

I sincerely hope there is additional information or another explanation, because otherwise this scenario makes very little sense from a any standard of diving: recreational, cave-diving and decompression-diving.
I can’t comprehend any of it !!!!

I think it was completely preventable but it is a good example on why you should read your dive computer manual.

They were doing a cenote dive, but he stopped looking at his dive computer because he couldnt read it due to low light. If you press the only button it i lights up, but he didn't knew it, so they decide to follow the local guide profile. Also he didn't change the settings from salt water to fresh water, so the computer was also working with a little less depth than the one they actually were diving at. Something preventable if you read your dive computer manual. At the end of the dive the guide surfaced without doing a safety stop so they skipped the safety stop too.

At night they start feeling bad, dizzy and vomiting and I ask them to text me their data from their dive computer. They surfaced with a gf of 85. Their default computer config was gf 85/85. Adding the margin of error of not changing their computer from saltwater to freshwater they probably should have done a deco stop or at the very least the safety stop.

In summary, READ YOUR DIVE COMPUTER MANUAL. Only YOU are responsible for your safety, follow your computer and do your safety stop even if the guide don't do it.

Edit: It was also their first time diving on freshwater and had a couple of rapid ascents due to not being able to controll their buoyancy as good as saltwater. The dive computer says the biggest one was from 5 meters to 2,75 meters, this could also be a factor

Sorry for the rant, Im equally worried and angry and english is not my first language.

The dive shop I teach at has started requiring instructors to own their own tanks. I was wondering if this was at all common in parts of the US, since my previous dive shop and the dive shops of some of my friends on another coast do not.

EDIT: I’m in Florida if that helps.

Shearwater just announced the Perdix 3 computer with an AMOLED screen, 6x faster bluetooth compared to Perdix 2 and software improvements.

In bali for 10 nights , was thinking of scuba diving at nusa penida but people said it isn’t safe so thinking about padang bai. Most of us haven’t done it before, others have done once. Are there any places where we can train and then dive with the instructors? We have 3 nights remaining out of the 10, one will be in seminyak right before our flight. Any suggestions, advice is greatly appreciated!!

I am sooooo close to my 100-dive mark, so I'm here for thoughts/opinions...

I have two Discover Scuba dives that I did pre-OW certification, and 4 dives that were required to get my OW cert. I know most people count the 4 dives required for my cert, but should I count the 2 Discover Scuba dives as well?

Just thinking of planning a trip and I always like to get more training when I do a dive trip!