I would think suction anchor is better. I would anchor boats that
would be mostly synthetic foam with a fiberglass resin or ferrocement
hull. It might be possible to find some fallen containers, in the water,
or purchase some (40’ for $800) and build a synthetic foam hull around it,
so thick, that even if the container is full of water, it would still float.
Then coat it with fiberglass or ferrocement, and anchor it in deep water
with a suction anchor.
Heaving is possible. Electric winches are nice, and the good old way
is still available.