Ok, than I would recommend south of Boston. If you go north you might have problems with provisions within walking distance.
One place would be Marina Bay in Quincy. It is a well protected marina with a large breakwater. The approach channel is about 10-13 feet iirc. There are plenty of restaurants and a small general store for provisioning
. This is close to Boston, about 30 minutes without traffic but there is always traffic. The channel is narrow and very shallow immediately outside of the channel. It is well marked. We spent a night there with friends recently and it was very nice.
But the real place that meets your list is Hingham Shipyard. This is my current
marina and you can't beat the location. It is a little further south but the commuter boat from Boston comes in at the marina. So you could take a water
taxi from Logan to the commuter boat and the commuter boat to the dock
. Less than $10 per person. There a four restaurants right there that you can walk to. Two full grocery stores, one is Fresh Market with unbelievable fresh meat and seafood. The other is Stop and Shop which has really good prices for the area. There is also three marine
stores within walking distance. The cost is about $135 a foot for the full season but they will do a prorated amount for less than a full season. Or more if you are like me and stay longer. It is a full service
yard and you can winter for $55/foot for pull, pressure wash, storage
and launch with a 10% discount if you do the full year. The down side is they can be very expensive for service
. You can bring in your own guys but they have to pay the yard fee. You can do your own work including sanding
and painting the bottom.
Let me know if you have any questions.