September 2017
« Jun    

Older Articles

Working the Tides in the Pacific Northwest

So many horror stories about paddling the inland waters of the Pacific
Northwest involve tidal currents and opposing winds that I thought I'd take
a moment and illustrate how to better predict your likely paddling
conditions in, say, the San Juan Islands in summer.

Even people raised in the Northwest can be naive about the dangerous nature
of the currents in WA, BC and Alaskan inside waters. The conditions are
predictable (northwest wind possible in the afternoon on a fine spring or
summer day or southerly winds likely on any rainy one) and the currents are
well known (tide and current tables). And the nastier rips are even shown on
charts! Yet every year a few people get into serious trouble. Probably lots
more just miss.

Remember that when the wind opposes the current any waves are likely to be
closer together and steeper and have a greater tendency to break (more
whitecaps). The stronger the wind and the stronger the current, the greater
danger for the paddler. And just like a river can have areas of calm and
areas of whitewater, even open water in the NW can have breakers when it
travels rapidly over obstructions on the bottom. The closer to the surface
these obstructions are, the more likely you will have serious white water.

Even the relatively open area between Fidalgo Island (Anacortes, WA) and the
San Juans (Rosario Strait) can have an area of 5-foot breakers with 3 knots
of current to sweep you into them (and onto a reef!). Think "rapids" on a
river and that will give you an idea. Yet lots of folks think nothing of
hopping into their Loons and setting off across this stretch.

The paddle between the north shore of Orcas Island and the very popular
Sucia Island has a reef and area of "rapids" where there has been at least
one fatality.

Rips are areas where opposing currents meet and are characterized most often
by triangular-shaped waves that appear and disappear suddenly. Paddling
through a large rip can be difficult because the waves are irregularly
shaped and may not have a pattern. One could just poke up underneath you
suddenly and then, just as suddenly, disappear. In the NW rips are often
found in narrow passages between islands, off points, and around underwater
obstructions. Generally, the more current, the more dangerous the rip. And
generally, when there is a large tidal range (the difference between high
and low tide) there is more movement of water and more current. This doesn't
just apply to the San Juan Islands but to any body of water constricted by
islands and points.

Most popular paddling areas aren't too complicated; what's the weather and
how far is it? The first thing I think about when I'm paddling these NW
waters is not how far the paddle is or even what the weather is... I think
first about the tidal currents and second the wind. THEN I worry about how
far it is. Because done right, in the right conditions, you can ride
currents all the way.

We are planning a 4-day paddle at Orcas Island this summer and to select the
dates I looked through an on-line tide table to find 4 days where the
smallest high/low tidal range at Friday Harbor occured during the times we'd
be most likely out paddling. You are a lot less likely to run into a
dangerous situation when the tidal range (the difference between high and
low tide) is small and we're just going to be gunkholing the shorelines
anyway. Okay, maybe a paddle to Jones Island for lunch.

For those of you who live in areas where there is only one high and one low
tide a day, the inland waters of the pacific northwest commonly have two of
each. Just makes life more interesting. One high and one low are generally
lots bigger than the other. These pairs occur at different times on
different days. If I'm planning a paddle where I don't want a lot of tidal
range I look at the tide tables to get the smaller high/low pair to coincide
with the times I'm going to be on the water.

Here is an example of the tides at Friday Harbor for August 1, 2006 from

Day        High      Tide  Height   Sunrise    Moon  Time      % Moon
           /Low      Time    Feet    Sunset                    Visible

Tu   1      Low   5:05 AM     1.7   5:47 AM    Rise  1:48 PM      36

     1     High  11:24 AM     4.6   8:49 PM     Set 11:25 PM
     1      Low   3:32 PM     4.0
     1     High  10:13 PM     7.2

The total tidal range over this day is about 5 feet and that mostly occurs
in the middle of the night when we aren't likely to be paddling. From 5am
until 3:30pm  - that's over 10 hours! - there is only a 2.3 foot tidal
range. This translates to not much water moving back and forth and, ergo,
little current. Even better, we can paddle with the flood tide to a nice
lunch spot and then paddle the ebb tide back home. But neither direction
would have enough current to make it difficult to simply turn back. And for
over four hours there will be only a .6-foot change in tide!

Now let's look at the next week, August 7th:

Day        High      Tide  Height   Sunrise    Moon  Time      % Moon
           /Low      Time    Feet    Sunset                    Visible

M    7     High   1:13 AM     7.4   5:55 AM     Set  3:01 AM      91

     7      Low   9:54 AM    -2.0   8:40 PM    Rise  8:16 PM
     7     High   6:14 PM     7.8
     7      Low  10:29 PM     6.6

Just seven days later the situation is entirely reversed. During the times
we might like to paddle (namely, daylight) there is almost a ten foot tidal
range in the space of 8 hours and all in one direction (flood). This
translates to a lot more water moving and a lot more current. Plus we will
have to slog across the mud flats to launch on that -2-foot tide at 10am. On
the other hand, if you want a nice evening paddle you'll have only a 1 foot
tidal range between 6:30pm and 10:30pm.

Even with smaller tidal ranges and their lower currents it's still possible
to get into trouble with contrary local currents. The tidal range - and the
times of high/low water - is not exactly the same at Orcas Island (which
isn't on anyone's tables) as it is at Friday Harbor. And there can be some
interesting variations in currents that would not affect a motorboat but
might make life a little more exciting for a kayaker. But your chances of
encountering life-threatening rips and overfalls are much lower when there
is a smaller tidal range. Just plan ahead. The Internet makes it easy.

Let's see... nap time is generally 1 to 2pm... so....

Craig Jungers
Royal City, WA