I have been diving Cozumel since the mid-80's. In fact, I will be there next week. I have never worn anything thicker than a 3 mil suit and have always been warm (even down to 232 ft!). Most of the folks I dive with wear little or nothing more than trunks and a T-shirt while diving there. But, I tend to chill easier! I haven't worn gloves there in many years. Some of the dive ops ban them and I find you deliberately avoid touching things if you are sans gloves. A hood is definately not needed.
