As a practical hiding spot, one could probably hide a short boat inside the tunnel to Pickerel Cove and not get caught.
Another good spot would be one of the empty slips at Irwin Marine in Laconia. Their sign out front says 'slips available.' Plus, they have a very nice bathroom with lots of hot water and a huge, old, marble sink.
Another good spot: tied to the dock of a 2million dollar mcmansion. Lots of time,, those big homes have nobody home.
Blending into a mooring field sounds doable, too. As long as your boat blends, it's just one more boat out the...re.
