🦠 Algae Wiki — worldwide dive waters

These are the algae most likely to affect a diver — the ones that cut visibility, turn toxic, or foul a dive. Out of the tens of thousands of algae species in the sea, the vast majority are microscopic, harmless and invisible to you; this guide is curated down to the characters you'll actually meet in the water. Split into harmful (toxin or serious kills) and non-harmful (nuisance / viz only) — each entry leads with the diver / spearo take.