May not be exactly what you are talking about but I worked with a guy before that did underwater welding. You can only do it for 3 years I believe for health issues but can make piles of cash in those 3 years. He only worked about 6-9 months a year after that. I would think that jobs in Cabo or St. Marteen, may be good,, there are probably tons of kids that want those also so they may be harder to get than you are planning.