I think a problem with snorkelling is that you loose all sense of where you are because its so easy to get engrossed in watching the fish.
I swam into some coral in Tobago, whilst snorkelling, cut my knee and then stupidly put my hand on to the coral and cut my hand as well. When you see your blood in the sea water because you are still looking under water it is a bit of a shock.
Like you Barry, I had to walk back up the beach to where Helen was sunbathing, with blood coming out of my knee and my hand, mask still in place on my face and all I got when she saw me was " trust you, its always you who does stupid things". Not one ounce of sympathy
. I would have at least expected an " Oh dear, what have you done, that looks nasty".
A lady next to us was a nurse and she advised me to get it cleaned up with antiseptic cream immediately because she said coral can cause infection.
So there I was, on a lovely tropical beach, with my hand and knee bandaged up for the next three days.