Has anyone else noticed any discrepancies between the predict times for current turns and speed between the XTide program and the Canadian Tide and Current Tables published by the Canadian Hydrographic Services (CHS) or your local authority? Today (Friday September 19) I did a check for the current speed and times of the turns at Race Rocks in Juan da Fuca Strait. I found a difference of 45 minutes between the predicted morning maximum current. In the afternoon the difference in the predicted turn is 22 minutes and 26 minutes for the predicted maximum current. Here's the break down. XTide turn to flood 0550 CHS turn to flood 0545 XTide Max/speed 0914 +3.01 CHS Max/speed 0830 +3 XTide turn to ebb 1243 CHS turn to ebb 1305 XTide Max/speed 1636 -2.57 CHS Max/speed 1610 -2.9 I added one hour to compensate for day light savings times to the predicted times in the Canadian Tide and Current Tables. I've sent an e-mail to the folks who developed the XTide program asking them to explain why such a large discrepancy? As a kayaker I find a difference of 45 minutes a bit disconcerting. I like the XTide program, it can save a lot of time, especially when it's loaded on a Palm Pilot; a number of local guides are using this to quickly determine the local tides and current. I've used it to double check my Tide and Current calculations in the past, but my confidence has been shaken so I'm going to stick with the CHS Tide and Current Tables. I guess that's why the XTide program comes with the warning that it's not to be used for navigation. I'll take accuracy over convenience. Gordin Warner *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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