© 2008 Lowry Bay Yacht Club
• Seaview Marina
• Wellington
• New Zealand
Lowry Bay Yacht Club
GENERAL
Cook Strait is a natural wind funnel bordered by high geographic features
on the North and South Islands, and at times creates a formidable gauntlet for boats
sailing to and from the South Island. The following information is provided to help
you cross the Strait safely.
WIND
Wind direction in Cook Strait is normally NW or S to SE. Storm force winds occur
on average about 25 times a year. Gale force NW winds are usually very localised,
but S gales affect the whole Strait. SE gales are more pronounced on the western
side of the Strait.
TIDAL STREAMS
Tidal streams in Cook Strait generally flow towards the NW for 5 hours
and SE for 7 hours. However, they are unreliable and the surface currents are affected
by prolonged periods of strong winds and the shoreline configuration which can cause
counter currents if close inshore.
High water occurs on the western side of Cook Strait about 4 hours later than Wellington at spring tides and slightly less at neap tides. This difference causes the strong streams. The streams are stronger during spring tides, which occur at two weekly intervals, when high water Wellington is about 0600 and 1800.
Tidal stream predications for Tory Channel have generally been found to be very accurate.
SEA
Broken water is experienced in different parts of the Strait. This is caused
by the cold north-
SAILING INSTRUCTIONS
The combination of broken water and strong wind gusts between
Sinclair Head and Cape Terawhiti make it advisable to transit this section of the
passage (commonly known as The Rip) at slack water. This section of your voyage is
generally the most uncomfortable and should not be attempted by small craft or the
inexperienced except in favourable conditions. Strong southerly winds with a SE setting
tidal stream can make this area a real horror show, and in the interests of safe
boating and harmonious crew relations, should be avoided. The times given are assuming
a speed of 6-
Travelling Westbound
Leave Wellington to arrive at Sinclair Head 1 hour before HW
Wellington. You will then have a favourable tidal stream across Cook Strait.
Alternatively, leave Wellington to arrive at Sinclair Head 1 hour before LW Wellington. You will then have an adverse tidal stream across Cook Strait, but this may be preferable in northerly winds. Tory Channel will be reached at slack water.
Travelling Eastbound
Leave Tory Channel 2 hours after the tidal stream commences
setting E. You will have a favourable tidal stream across Cook Strait-
Alternatively, in southerly winds leave Tory Channel as the tidal stream starts setting
W. You will have an adverse tidal stream across Cook Strait, but this may be preferable
in southerly winds. Cape Terawhiti-
TORY CHANNEL EASTERN ENTRANCE
Ships make frequent use of Tory Channel and you must
keep clear of the mid-
Ferry and shipping timetables are subject to seasonal changes, and skippers are reminded that they must keep clear of all shipping lanes at all times.
RADIO
Ships maintain a listening watch on the following frequencies:
Within Wellington Harbour limits: VHF Channel 14
Within Marlborough Harbour limits: VHF Channel 19
Cook Strait: VHF Channel 16
CLEARING MARKS
Thoms Rock
This is situated between Karori Rock and Sinclair Head
and lies 0.35 miles (650 metres) outside a line joining these points. Rock hopping
in this area is not advisable.
Day: Keep Pencarrow Lighthouse visible through Sinclair
Head until Karori Rock is open from Cape Koamaru.
Night: Keep Pencarrow Light visible
(red or white) until Tongue Point Light changes from red to white.
Sinclair Head
Day: To pass about one mile off Sinclair Head, keep Pencarrow Lighthouse
(lower) and Old Lighthouse (upper) in line.
Night: Keep in the white sector of Pencarrow
Light to pass 0.7miles off Sinclair Head.
Checking on Tidal Set
Day: Observe Karori Rock relative to Sinclair Head or Turakirae
Head. Observe Tory Channel entrance relative to Mount Stokes.
Night: Observe Tory
Channel Entrance Leading Lights.
