I bought this item after reviewing several other comments. I'm 6'1, 225 and typically wear an XL tee shirt. I ordered this in a XXL and it fits fine.

I plan on wearing this skin to scuba in the Caribbean and Florida panhandle for the next few years. The water temperature is much too warm for a typical wetsuit, whether short or long. Additionally, scuba equipment can sometimes cause rashes to your armpit area, so this should be a great purchase all around.