Almost exactly two years ago I wrote this article about the staying safe in the heat. I’d like to call attention to this piece again, because, well, it’s really roasting out there. I’ve already laid out a few personal health and well being tips, so now I’d like to focus a little bit on your life support equipment. Sure, you can stave off heat exhaustion, but what happens to your stuff in weather like this?
Today’s gear is durable, dependable and well made. Considering that most diving around the world takes place in tropical locals, the equipment is certainly designed to handle the heat. There’s a few things you can do to help ensure that your setup stays in tip top shape. My gear mantra is always “if you take care of your gear, it takes care of you”.
The less sun, the better. No, your BC isn’t going to fade immediately in the sun and your regulator hoses aren’t going to liquefy, but it’s best to keep stuff out of the sun when possible. If you gear is all set up, but you’re not jumping in for a bit, you can always cover it with a towel to help keep some of the sun off. Being in direct sun isn’t just going to eventually fade colors (think years though, not days), but it can have a lot more immediate side effects. Most of us have a lot of black on our gear. Black objects will heat up faster in sun light, and some pieces of gear are a lot more sensitive to the heat than you might realize.
Take your compass for example. The dive compass is a surprisingly accurate and finely tuned device. Have you ever had a dive compass for a while, then suddenly found an air bubble in the compass? No, you don’t have a hole in it, it just got too hot one day. Many actually come with an air bubble from the factory. This allows for the natural expansion and contraction of the liquid filling (due to hot or cold) to occur without any damages to the compass. After a while, especially if they have been through a few good sun bakes, just about every compass out there will develop at least a tiny air bubble. What happens is that the compass housing and liquid will expand when hot, but won’t contract back to the exact same dimensions when cool. This little gap that’s left shows up as an air bubble. For the most part it’s harmless, but if the bubble keeps growing you might want to look into replacing the unit.
Dive computers are a hearty lot, but occasionally in extreme heat the LCD displays start looking a little funny. For the most part the return to normal once cool, but I treat mine much the same as the compass. Conveniently I have them on the same console, so it makes it easy for me to keep them shaded and cool.
Your next most sensitive piece of gear I’d actually say would be the tank. No, the sun isn’t going to cause the tank to melt. Nor will it weaken the metal or any of that. What often does happen though is as the tank heats up, the pressure will rise in the tank and you could blow a burst disk. According to rules of Charle’s Law as it applies to SCUBA tanks, for every one degree temperature change, the tank pressure will change about 5-6 PSI. It’s not unheard of for the trunk of your car to reach 140 degrees in the kind of heat we’ve been having. If your Aluminum 80 filled to 3300 PSI let’s say (yes, technically an overfill, but not an uncommon one) at 70 degrees in an air-conditioned shop, you could be looking at a 420 PSI pressure difference. That could be more than enough to set off a burst disk. Now, the burst disk is designed to go before the tank does and they are easily replaced, but it’ll sure ruin your dive day when there’s no air left in the tanks. It’s also really loud and scary when it goes off. Trust me.
It’s common for people to give shop workers the stink eye in weather like this when they don’t get the 3500 PSI fill on the aluminum tanks that they are used to in cooler weather. Don’t hate us! We’re just trying to keep things from going boom! Also, if you jump in the water and notice that in the 30 seconds it took you to reach the bottom you used up a ton of air, don’t worry, you’re not suddenly woofing more than usual. As the tank cools, the same rules apply and your tank pressure will drop.
Chances are your wetsuit isn’t going to melt, but it can get steamy hot. Prolonged exposure to heat and sun will prematurely degrade the neoprene, so keep that in mind when you hang it out to dry. Also, be careful about putting on a wetsuit that’s been baking. Hot rubber hurts! Plus, you’re not helping the possible heat exhaustion/heat stroke scenario if you’re putting on rubber that’s already toasty.
Remember your sun screen, and remember to drink plenty of water! Be safe, and have great dives.