Yesterday I experienced what I considered disgusting, gross behaviour on the boat by another diver. I was the last diver out of the water and was standing on the ladder toward the rear right hand side of the boat, removing my fins.
Some guy (and it's usually a guy who I have seen exhibit this behaviour), sitting at the front of the boat on the same side I was, leaned over, horked a gigantic luggie and then immediately proceeded to blow out two gigantic streams of snot from his nose into the water. I was down current (in a fast current) and nearly puked as these gobs of nastiness made their way straight toward me. I did some sort of contortion myself to avoid them, as he apologized to the people ON THE BOAT!
Now I can understand if someone is seasick and needs to hurl, that they can't always get the timing and velocity just right. But there was absolutely NO need for this guy to do this while I was still in the water. He could have waited the 30 or 40 seconds it would have taken me to remove my fins. Or, he could have gone over to the other side and ministered to his needs.
Consider this a plea...please exhibit a little consideration for other divers still in the water. And if you are a DM, and see this, ask your rude, inconsiderate client to hold off a minute or so. And if you are married to one of these inconsiderate goofs, well, you have my sympathies. But maybe you could wrinkle your nose at him.
One of my least favorites is having a boat-mate prime his pee-valve while on-deck. . .