Saw a sea snake in Tenacatita, Jalisco, one winter. It was a small one, found by some Mexican boys who were playing with it as it moved about in somebody's Croc footwear. I had a general book on fishes of the Americas, with one single entry right at the back, concerning snakes. The boys had one! I mentioned how dangerous their snake could be, that they should let it go, but to take it to the rough side where swimmers seldom took to the water. They had had some fun with it, and the small snake seemed to enjoy the attention. The book mentioned that this snake, with one, long yellow stripe on its underside, was prevalent in all tropical oceans of the world, and its bite was very venomous.