Notice to Mariners (No.14 of 2019) reminds skippers that:-
a) Vessels over 220m LOA transiting between Hook Buoy and Prince Consort Buoy (known as ‘The Precautionary Area’) are entitled to a ‘clear channel’ with unimpeded passage ahead.
b) All vessels over 150m LOA navigating within the area are entitled to a Moving Prohibited Zone (MPZ) extending 1000 metres ahead of the bow and 100 metres either side.
c) Vessels more than 180m LOA shall not pass each other between Hook Buoy and West Bramble Buoy.
d) To indicate the presence of an MPZ vessels over 150m LOA shall display a black cylinder by day and, by night, 3 all-round red lights in a vertical line.
e) Whenever possible a Patrol Launch (VHF Channel 12; Call Sign ‘’SP’’), showing an all-round blue light, will precede all vessels over 150m LOA within the Precautionary Area.
f) Absence of a patrol launch does not invalidate a vessel’s MPZ.
More details, including the effects of flood & ebb tides, can be found at http://www.southamptonvts.co.uk/admin/content/files/NTMs/2019%20No%2014%20-%20Port%20of%20Southampton%20-%20Precautionary%20Area%20(Thorn%20Channel).pdf