What chest sizes for regular and oversized?Answer: The universal fits a chest size of 30"-52", and the oversize fits a chest size of 40"-60". By Kirsten M. on October 2, 2017
The claimed chest size for the regular is 30-52. In reality it doesn't fit right with a chest size smaller than 44, it will be much too thick and bulky.
It is very buoyant. I have only used it for kayaking, but it should work fine for any water sports. The only difference from a regular life vest is that the bottom 4-5 inches on the back are mesh, not padded, making it more comfortable for kayakers.
This oversize is large or close to xl. They fit fairly snug. Unless you are quite small, this will fit most adults.