Wishing for miracles like free energy has a long, long tradition dating back to the pleistocene. If you want magic energy from seawater, why not also wish for transmutation of lead to gold, immortality, corn flakes that never get soggy, stocks that only go up and a zillion other things.
FWIW, a few years ago I saw someone trying to swap a cold fusion generator for a perpetual motion machine. Not sure who was getting the better part of that deal :>).