Jerry,
Your just lucky you did not catch string of lobster pots or some of the other crap discarded in that channel by commercial guys & locals. They've been doing it for forever. Pulled up a transaxle there back in 1996 and some coiled cable in 1994. I had a friend pull up a pick up truck cap. Doh' Nice spot, good restaurant, but a horrible place to anchor unless you want to bring up discarded crap and lobster traps. Don't know why the locals there treat it like a trash dump but they have. We now anchor in Sebasco up near the head of the harbor and take the dinghy up there.
The transaxle took half a day to get away from and the locals just thought this was "normal" bottom stuff.. Nice spot, quiter than Sebasco, but uncertain holding due to clutter. The holding is good though if you don't pick up trash. If you like that area there are a few nice spots up river or you can go in behind Hermit Island around West Point but I will warn you it gets BUGGY in there... Beautiful until dusk or as my wife calls it a (BUD) anchorage...