LNM01-505745
Received 23 Sept 2026, 00:00 UTC
Warning text
PORTSMOUTH TO CAPE ANN - PLUM ISLAND SOUND
General / Hazards To Navigation / Shoaling Reported
Shoaling exists in Plum Island Sound between Plum Island Sound Entrance buoy 4 (LLNR 9310) and Plum Island Sound Entrance buoy 6 (LLNR 9320), aids are not properly marking best water. Mariners are advised to use caution while navigating this area. All of Plum Island is particularly susceptible to shoaling, the area between 4 and 6 being the worst at the mouth of the channel. Last year the unit partnered with the harbor Master moving the aids to mark the best water. Even though the aids are in the best possible locations that water is still shallow at low tide and mariners should use caution while navigating in this area
USCG Northeast District Local Notice to Mariners 45/2026