Judging from the (limited) SO responses, coupled with what i was told by the guy i am working for, the degradation of the cables makes the idea cost ineffective. Also, and i cannot stress this enough, in Maine you do not fluck with the Lobstermen. You don't even do anything that could be construed as tampering with their routines. Dudes are the hells angels of the small boat world. The thought of trying to explain why i look like i am cooking their profits before they can haul them up gives me the willies...
the water is a flat 40 F. average depth is 50' in the center. The Reach has an average flow (in/out) speed of 6 knots (underwater). The Reach moves about 1 trillion gallons of water every 6 hours between high and low (may sound hyperbolic; look up the Moosabec Reach). The tidal variation between high-to-low is ~14'. In a perfect world i would submerge a tidal generator in the deep point and power my island project AND Jonesport-Beals, but as i stated before Lobstermen do not like change, so i am pretty sure a giant underwater propeller is not on the menu... i digressed; the only swimmers are the seals, the sharks, and the daft.