1. Harass Marine Life
This one really should be a no-brainer, and yet we do see all too often videos uploaded to YouTube showing people entertaining themselves by harassing marine wildlife, we should never entertain like this on a dive.
So just to reiterate: don’t grab animals, don’t hold them for photo ops, don’t go for rides on dolphins or turtles, and don’t force puffer fish to inflate (it can be fatal to them).
It is bad form, you’re setting a terrible example for other divers, and many organizations will actually revoke your license, at least if you’re a professional diver, such as an instructor or divemaster.
2. Pick Up Coral
This one should be a no-brainer, but it still happens.
Coral grows slowly, and a snapped-off piece of a few inches can take many years to regrow. To make matters worse, some types of coral are at risk of dying if even small piece are broken off, killing off a major part of the reef they’re on.
Quite quickly, we’d find ourselves with severely diminished coral growth on reefs around the world. But there’s more to this than just not breaking off living coral.
Picking up dead corals off the seabed isn’t much better. These broken off pieces are also part of the ocean’s ecosystem, so removing them also removes resources that other parts in that ecosystem depends on.
And I know you only pick up a single piece. But so does the next diver. And the one after that. And the one after that.
3. Land On Stuff
For many divers, and in particular novice ones, maintaining neutral buoyancy is tricky.
In particular when you want to get a photo of something, and need to keep completely still. So from time to time divers will “land” on the bottom to rest or stabilize themselves. This is fine if you’re landing on a clear sandy bottom, but not so if you land on corals, anemone or other sensitive plant and animal life.
Before you set down, look at where you’ll be landing and make the assessment of whether it would be OK or not.
Imagine yourself diving without a wetsuit. If you’d be OK with putting your exposed skin on whatever surface you’re eyeing, it’s probably OK to do so in a wetsuit.
Spotting marine life, in particular the large, pelagic ones, like sharks, is a real crowd pleaser. But because animals usually don’t follow timetables, sightings are never guaranteed.
For many of us divers, that’s part of the charm; you never know what you’re going to see (maybe nothing). But sometimes, out of impatience perhaps, some divers and dive guides will try to stack the odds in their favor by chumming the water to attract certain species, usually shark, or they’ll bring chum on a dive to draw animals closer. And this is always a bad idea.
Chumming means animals start associating divers with food, which will make them less careful when approaching them, and some humans seek to cause harm to animals.
Also, feeding in particular sharks can cause feeding frenzies, where humans can get bit. Too many shark bites around the world are actually caused by humans chumming, but ultimately, it is the shark that gets blamed.
5. Take Souvenirs
There is no better souvenir than a memory, or a photo. Picking up stuff from the ocean, rocks, pieces of coral (see point #2), or artifacts from shipwrecks.
Sure, if you come across something that is obviously trash, bringing it up with you and throwing it out is cool, admirable even, but anything else should be left in the ocean. Some things are a part of the local ecosystem, others serve as shelter for marine wildlife, and still others are part of the dive experience, and if you take it with you, you’re essentially robbing future divers of that experience.
So while that centuries old wine bottle could probably look awesome sitting on your desk, leave it for others to enjoy, too (not to mention that it might be illegal to raise it, depending on the laws of the area).