You could try Hingham harbor. If you're trailering there's a free ramp right on 3A at the beach. Water to the left of the ramp and out towards the small islands doesn't seem to get alot of use. Just have to watch your tides. I would think a couple of hours on each side of high wouldn't be a problem but the bay pretty much goes dry toward the bottom. Check your charts.
A bottomless pit of bum information/ Death makes memories of us all...
I would have to agree with off Nantasket, most of the inner harbor is also loaded with lobster pots most of the summer, nice avatar by the way, I've seen about 30 shows back in the day