OCC CRUISING INFORMATION SERVICE

George Curtis, Blacksmiths Cottage, Aston Tirrold, Oxfordshire, OX11 9DQ, England

Tel/Fax:+44 (0) 1235 850794; e-mail cis@oceancruisingclub.org

 

Warning on the use of the Pacific Pass Atoll Calculator. This is a 1994 & 1997 one page report. A reference copy of the one page Pacific Pass Atol Calculator is held in the CIS Archives but will not be published on the Web, becasue its use is not recommended. Scanned copies may be requested by e-mail.

John Driscoll of Moonlight of Down comments on the use of the Pacific Atoll Pass Calculator in the Tuamotus.

Having looked into the above carefully and compared the information regarding slack water at Manahine, Ate and Rangiroa, and consulted boats using passes on other atolls, I am not enthusiastic about its use.

The most reliable method is to use the Admiralty Tide Tables to ascertain the times of L.W. and H.W. for the particular atoll. In general slack water occurs one hour after L.W. and H.W. and this is the best time to enter/leave most of the passes. There are some passes that are significantly different from this rule.

Comparing the information obtained from the Pass Calculator with that from the tide tables over a lunar month there are significant variations in the times of slack water for a given atoll. There is also a significant variation of tide times between the atolls which is not fully taken into account by the Pass Calculator.

Bearing in mind the short periods of slack water in which the passes are manageable in fresh/strong trade winds the Pacific Pass Calculator is of limited value. The first choice of information must be from the Admiralty Tide Tables, with the Pass Calculator only being used where tide table information is not available from some source. (Info generally obtainable from another boat in the Marquesas).

In spite of the large number of yachts now visiting the Tuamotus it remains a challenging place to take a yacht. This year (1997) many boats had extremely worrying times negotiating the tide rips when getting pass timings wrong and had insufficient engine power to extract themselves. There remains the old problem of being caught inside in bad weather unable to move on the lee side of a 20 mile fetch

The OCC Cruising Information Service is provided by the OCC. The information is supplied to the OCC by members and is for OCC members only. The date given in the above is the date that the members supplying the information visited this place and the information may have changed at any time. The OCC has taken no steps to verify the information, which should be confirmed independently. The OCC accepts no responsibility for the accuracy of the information and cannot be held liable for any damage howsoever caused whether directly or indirectly or any consequential losses.