Re: [Paddlewise] Tidal flow for west coast of Canada

Evan Dallas wrote:

>I've heard from one paddler that in addition to the local tidal
>currents that flow into and out of the various bays and inlets on the
>west coast of Canada (I'm mainly interested in Vancouver island),
>there is also a general tidal flow that runs north and south along the
>entire coastline.  Given the "diagonal" alignment of Vanc isl (i.e.
>running from a southeast to northwest orientation), I'm guessing that
>the large tidal swell off the coast probably pushes water more or less
>due east, which would then be diverted along the coast towards the
>southwest (due to the diagonal alignment); with the opposite happening
>as the tides pull back -- but that's purely my own speculation.  In
>actual experience, I haven't noticed much of an effect.  Does anyone
>have more definitive information (or links) that would explain this
>further?

The only "general tidal flow" is from the ocean inland. This is what
generates the currents where geography restricts the flow. (For those
unfamiliar with the area, the currents reverse 4 times every 23 hours with
tide differentials of up to 16 feet.) There is an ocean current, however,
that flows up the coast, NW to SE in the summer, reversing in the winter.
Perhaps this is what you have reference to. I soloed around Vancouver
Island a few years ago in a small sailboat in June. I traveled most of the
outer coast with other sailboats and we always took different paths from
bay to bay. I always opted for the close to shore route, anchoring and
going to shore where I could, whereas the other boats went several miles
out. I found reverse, eddy currents within a mile to half mile of the
shore, sometimes as much as three knots, where by tacking out a mile, I
could gain the favorable current that the other boats were having. By
comparing GPS speed to my knotmeter, it was a real education in how these
currents travel. Off Estevan Point, for example, I was caught in a 3 knot
current that ran due west. June is a transition month so I'm not sure what
one might expect at other times of the year, and in the Pacific in recent
years, no two years have been the same.

One thing is for sure, many of those inlets run many miles deep and with a
spring ebb tide and any ocean swell, the water can stack up very steep at
their entrances.

Al Gunther, Kingston, WA  <---- 47° 48.1'N, 122° 30.0'W




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