What Not To Do on a 2 Hour Cave Dive

This may be a long blog, so I'll get to the punchline first. What not to do? Don't go diving without adequate thermal protection! In cave diving the problem is compounded because you cannot simply leave the water when you first notice you are too cold. You have to stay cold and finish your dive... COLD.

I'm in Cozumel again, lovely beautiful Cozumel. Aaahh. Nice place, but humid and hot in the summer. I'm unabashedly indulging in air conditioning every chance I get. While here, I've already made arrangements for my winter trip to stay in the usual departmento (a mere $450 per month) and bought round trip plane tickets. American Airlines was having a sale up until July 7th, and I got my tickets for the unbelievable low price of $319 including taxes. And that's for a 2-1/2 month stay. Normally the tickets are closer to $550.

Yesterday Brad and I did two dives in Aerolito de Paraiso with stage tanks. We did both dives down Sulfur Falls and then in both directions at the "T" in Wonderland. Pretty much the same kind of plan Glenn and I did last winter. Brad has a knack for finding these nifty side passages with tons of speleothems, so I saw many more beautifully decorated parts of Aerolito than ever before.

Our first dive used standard air in our back gas and 36% nitrox in the stage bottle. Maximum depth was 71 feet with most of the profile in Wonderland at around 55 feet. Water temperature seemed to hover mostly around 82-83 F, with most of our time spent in the salt water layer. Brad had two Ikelite 400's on his camera (the really big really powerful strobes) and I had a 3rd one with a remote sensor on a 3 foot pole. He would find a wall of stalactites or some other feature he wanted to photograph, I would watch his cave light to see where he wanted me to aim the strobe. I would then hold the strobe at about a 60 degree angle to his lens port and wait for him to focus and shoot 2 or 3 shots. Then move on. This is how most of the dive went. Total dive time: 116 minutes.

The second dive we had 36% nitrox in both stage bottle and the back gas. I decided the water seemed warm enough, why not ditch the extra 3 mil suit and dive only with one 3 mil. As soon as I jumped in the water I realised it might have been a bad decision and it was. At around the turn-around point I thought I was getting tired, and on the way back I could tell my energy levels were flagging. By the time I got to the safety stop in colder water above the halocline I was visibly shivering. Fortunately we had no deco obligation any time during the dive (great stuff, nitrox) so I only suffered through an 8 minute safety stop and then got out. Total dive time: 122 minutes, maximum depth: 78 feet.

We were back into town by about 7:15pm, a very long day. I was totally exhausted that evening. I even took today off diving. But tomorrow and Sunday (my last two dive days of the trip) I expect to be back at it, full strength. And with a full 6 mil of thermal protection!