NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Optimizing Ocean Current Crossings
From: Herbert Prinz
Date: 2001 Jul 11, 9:48 AM
From: Herbert Prinz
Date: 2001 Jul 11, 9:48 AM
This has nothing to do with Yves Arrouye's original question, the answer to which I do not know. But since the discussion of other sources of information about ocean currents has been raised, let me say that on this side of the Atlantic we normally use DMA Pub.106, "Atlas of Pilot Charts" as a planning tool. I only have those for the North Atlantic. They come in 3 sections (North Atlantic, Northern North Atlantic and Caribbean Sea). Each section contains 12 Mercator charts, one per month, ca 60cmx40cm large, divided into 5deg x 5deg squares, each square containing a windrose and a current vector, besides other information such as avg. wave heights or iceberg sightings, etc. If I get near the Gulf Stream, I call up Jenifer Clark and request a Gulfstream analysis per fax or e-mail, which is good for a few days and certainly worth the few dollars. So far, the Gulf Stream is my only serious ocean current experience. Although I once have been able to ride it for 3 or 4 days, thanks to good weather, on a passage from Norfolk, VA to the Azores, my general perspective on it is that of a cruiser (who has all the time in the world) or delivery crew (who can't afford risks), and therefore directly opposite to that of racer: The goal is to get through and out of the Stream as fast as possible! For this strategy you don't need a book, just keep a heading perpendicular to the current at all times. I have a related question: In the English channel, are there regulations that would prevent a small sailboat from taking full advantage of favourable tidal currents, such as having to cross shipping lanes in shortest time (i.e. perpendicular), etc.? Or is this entirely left to the discretion of the skipper? Is this a practical problem for a small boat crossing from, say, Calais to Dover or Ramsgate? (I mean the shipping lanes in conjunction with the tides, not the tides by themselves.) Herbert Prinz (from 1368950/-4603950/4182550 ECEF)