I am a big guy as well, same weight a little taller. I got mine from Bass Pro, it is a 4xl with 4 buckles and will fit over jackets and rain gear in the winter. I wear mine whenever the big motor is running and it is comfortable. I have tested it by jumping in the lake and just floating there and it holds me up with no issues. This is the 3rd one I have bought from them, sweat and sunscreen tend to wear out the part that go up around my neck.