Turn them into bridges.
Their most likely fate:
Can you imagine getting the oil-crud cleaned out of them well enough that you could live inside without constant dizziness?
You’d probably need a mixture of acetone, xylene, and salesman soul distillate, dispensed by fire hose, and months of work…
Assuming they can be cleaned out well enough, a floating fish farm would be an excellent use of them - move it around the ocean as one needs to find food sources and disperse waste, then deliver to market when mature.
Sealands. Lots of them.
Heard about a ship that ran aground nose first, just like in the illustration, in a bay that gets small to medium waves in the winter. Apparently it created a nice point break off both port and starboard sides of it. Still I wouldnt want to be the guy cleaning that gunk off the inside of the tanker.
Does Disney own the rights to Water World by chance? They could start a Water World Xtreme Xperience Summer Camp.
I’d send my kids. Indefinitely.
I have fantasized about this very idea for years, though usually it involves me getting the whole ship to myself, with indoor basketball court and auditorium, roof garden (and indoor solarium), art/music studio, etc etc.
Super villain command center behind the secret panel.
“When the oil runs out”
About that. Chances are good it’s not going to run out before we need to stop using it.
Yeah we know. Oil isn’t going to run out, but it will get too expensive to use for trivial things like moving you from point a to point b.
Sell them to the 3rd world and have them cut up for scrap.
What? I know that isn’t a fun answer, but probably the real one.
Coral reefs not an option?
The beachfront village idea would be cheaper to just build in the shape of a tanker.
The only responsible thing to do with them is recycle their metal when the cost of doing so is sufficiently inexpensive relative to other sources. Here or abroad.
More imaginatively: Extreme Tourism.
There may also be an unpredictable technological breakthrough that makes demand for oil drop precipitously, as demand for stone for toolworking or whale oil for any purpose has in the past.
Tanker holds are nasty toxic. Be sure that any residential/day care/etc. reuse involves appropriate clean up.
(keep your mouth shut and you can have the guest bedroom, all 10,000 square feet of it.)