No matter which calculation is right, that sounds like a heck of a lot of work and risk for a fish attractor. Just imagine going through all that and dropping it in a bad spot. We've all sank brush snd whatnot in places that should have been great honeyholes only to come up empty year after year. But at least those piles only took a few blocks to sink. 1500 pounds!!! My boat only weighs about 2500.