Things can go from "Woo Hoo" to "Oh hell" only too quickly.

My first thought is that the skipper should be wearing a pfd, even an inflatable type.

An inexperienced crew member driving the boat towards a swimmer worries me because of the possibilty of getting tangled up in a rotating propeller.

While nobody has mentioned it yet, if the skipper is safely floating, there are many other boats around that could possibly help rescue him if called on the VHF.

But this is a really valuable thread for me, a very poor swimmer (and) the skipper.