They're talking about surviving the ocean drops.
Which is feasible, people have survived days to weeks floating in the ocean before, it isn't like 30 seconds is an automatic death sentence. But they specify the possibility of showing up with critters circling, which could make things very risky since the wrong bite wouldn't even have to kill you immediately to fuck things up.
But, assuming that the only factors are ocean surface and wildlife threats, it's doable. You don't even have to swim unless things are pretty bad. Just floating and treading water for that long is realistic for anyone with a fair degree of mobility.
Unless it's crazy shit. Thirty seconds in a storm, shit can go bad fast on land. You magic your way back with lungs full of water, and it might not drown you, but you're not going to be doing great. Worst case scenario, you end up with some kind of infection as an outcome which could kill you.
Anyway, point being that the proposed scenario isn't purely about being wet. There's a stated assumption of danger since you have to survive the trips.
Yeah, it's a big fucking ocean and you aren't likely to land right on top of a breaching great white. But it ain't all that safe either.
Not that I'd turn it down, I'd go for it. 100 mil is plenty when it's tax free as stated. That's enough to maximize your chances at surviving it because unless something directly kills you in thirty seconds, you'll still pop back to where you can call an ambulance. Or, keep an emt/nurse/doctor/whatever on salary for those events to make sure you recover very well.
But, we all get old. At some point, you'll die. You have a bad enough stroke, and your next dip in the ocean becomes life threatening even in wonderful conditions. That's not exactly a reason to say no. Hell, it's a reason to say yes, because there's at least a chance that if you're stuck in a failing body, you might get lucky and wind up on top of a breaching great white.
So, yeah, I'm doing it, but I'm not fool enough to pretend that it's some kind of cake walk