I toyed with the idea of deep commercial diving in the mid 1980's, mostly because saturation divers made money like rock stars in the mid 70s and into the 80's. But the reality at the time was that it was not a matter of if you got bent, but when, and careers as active divers were very short. You could plan on debilitating issues with things like bone necrosis by your mid 40's. That already short career was also limited by years spend as a tender for relatively low pay until you got the seniority to actually start diving.
I don't think the long term effects have changed much in the industry, despite better technology, and you'll still have to pay your dues as surface support hoping for a chance to actually dive and make serious money.
In that regard, the more education you have the better over the long term. English lit isn't what I'd call a horribly marketable degree, but it's a degree and for many jobs that's all you need. The irony here is that it's often those general requirement classes that give you the rounding of experience and broadening of thought which underpins the requirement for a college degree in many jobs in the first place. They won't give a damn about the English lit.
In the offshore commercial dive industry, the major advantage of a degree are in terms of showing you are able to manage your time and are disciplined enough to finish a degree in the first place, and while it has nothing to do with welding, rigging, wrench bending or diving, once you acquire those skills as part of a diver training program, it's still something extra on your resume. Plus, once your career is over and you're limping around on bad knees and hips, having an actual completed bachelor's degree that never goes bad, will be far more valuable than a 100 or so credits that never amounted to a degree, as most of those credits won't transfer to another university, and even in your old university many of those credits may no longer count toward a degree.
So get the degree, even if it's in English lit. It will get you in door for any job that just requires a degree, and it will also get you into grad school for something much more marketable later on.
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In my case, I opted not to get into offshore commercial diving, but did inland commercial diving for about 20 years as a sideline business. The work was mostly inspection, salvage and recovery (with the occasional body recovery), marina maintenance, etc and while not terribly exiting it was always interesting, usually zero viz and quite challenging in it's own way. And at age 50 my joints all still work as advertised and I'm looking forward to another 20 years or so of active technical wreck and cave diving that I would not be doing had I went the offshore route.