Why Not? Don't feel bad about your body type. Everyone is accepting regardless. That's one of the unwritten rules of nudity. No body shaming. There are plenty of people with your body type on those cruises.
I once thought it would be sexually exciting to be among nude people until I went to a nudist camp in Southern California. It was all rather normal except people didn't have their clothes on. Everyone was pretty normal.
I even played tennis with this one lady. Those balls were flying everywhere!