I don't know what his circumstances were to have an air mattress at the beach but thinking about it now I think he or his party were using it as a float.

We were screaming for help and the crowd on the beach thought it was kids playing but he happened to have been in the area the whole time and saw us go out and he sprung into action.

This was in Rocky Point Mexico and I am 34 now. This was 20 something years ago. We were from Phoenix and he was from Tucson.