1. Opening your tank valve to dry your regulator.
This one comes in as a clear No. 1. Many divers, after a dive, attempt to blow the cap on their regulator’s first stage dry by holding it to an open tank valve. This achieves a few things, none intended. First, a hissing tank is quite loud and can actually damage people’s hearing. Second, the hissing tends to scare people — as loud noises often do — especially with a lot of pressurized tanks all around. And finally, while this action does dry the cap, it often works by blowing water droplets into the first stage, driving them deep into the sensitive parts of the mechanism. This is exactly what you wanted to avoid by drying the cap in the first place, so it’s better to simply blow on the cap before replacing it.
2. Pressing the purge button to test that your regulator works
This happens in the gear assembly stage, after people have attached the first stage to the tank. At this point, many people feel the need to press the second-stage purge button, to test that it works. Negatives are the same as those above, but most importantly, a regulator’s second stage is really only designed for underwater use, so pressing the purge button out of water can actually stress the diaphragm inside, causing it to stick and free flow. Take a few breaths on your second stage instead to test that it’s working properly.
3. Not respecting your place in line for a boat.
We’ve all been there: The dive is over and we’re all eager to get back onboard the boat and share stories/dry off/warm up. But we’re all in the same boat, so to speak, so respect your place in the line, be it the shot line or the line on the surface waiting to move up the ladder. This goes double for divers who finish their safety stop and time it with a dive ladder freeing up, then shoot from the depth like the shark in Jaws, snatching the ladder from the next person in line. Who, more often than not, is a slightly hypothermic novice diver, who really needs to get out of the water and warm up. Apply a bit of situational awareness and note if there’s a line. If so, respect it and take your place. You’ll be back on board, soft drink in hand and shark tales spilling from your lips, soon enough.
4. Diving with a snorkel (Again… this is personal preference)
Granted, there are various opinions on this. Some operations require a snorkel; others won’t permit them. Personally, I’m in between. There are a few situations where a snorkel comes in handy — for snorkeling, first and foremost. And some dive spots feature a long surface swim, using only bottom features to navigate. I haven’t found any myself, but I’m sure they exist. Snorkels can be useful if you’re waiting on the surface for a long time in rough seas, or if you need to conduct a surface rescue. For these reasons, I often put a foldable snorkel in a pocket of my drysuit or BCD. But during the majority of dives, snorkels just get in the way, becoming entangled in shot lines or yanking off dive masks.
5. Taking a deep breath on descent.
It’s a natural, physiological reaction; when we submerge, our bodies want to take in a nice big gulp of air. It’s almost an involuntary reflex. Almost. And we all do it at some point. But a big gulp of air upon descent can increase your buoyancy such that descending becomes impossible. Many divers over-weight to compensate, so they struggle with their buoyancy during the entire dive, use too much air, and probably aren’t in trim. It’s counterintuitive, but as you descend, exhale for the first 3 to 5 feet, then start breathing normally, and continue doing so during the dive.
You may have noticed that I didn’t include the bad habit of annoying marine animal life or destroying corals. I didn’t, because, thankfully, I don’t see many divers doing that, at least on purpose. But I do see the five bad habits I’ve included here pretty frequently, and they affect everyone’s dive experience negatively. But like I said, I’m sure none of us is guilty of these bad habits. Right?