Pine Island Bay is in Groton at the mouth of the Thames river (next to UConn). So a long way from Mystic.
With your draft
, you should be able to go up the Mystic river, through the drawbridge and anchor
in the shallow flats anywhere you want. If you don't want to wait for the drawbridge (once an hour during the daylight), you should be able to anchor
anywhere you want south of the railroad bridge and dinghy
1/2 mile up river to the downtown dinghy dock
. Your draft gives you many options.