Cordero Channel - 5 rapids in one tide

[Amgine]

I've been planning to write this up at some point, might as well do it here...

The inside passage of the Pacific Northwest involves traveling inside of Vancouver Island, Haida Gwai (Queen Charlotte Islands), and on up to northern BC coast and Alaska. This is mostly protected waters, so less concern about storms and waves than going outside. But it does have its own unique risks.

The southern portion, sometimes called the Salish Sea, is a nearly land-locked sea with thousands of islands blocking the path for tidal waters getting in or out of the basins. The tides travel via Juan de Fuca Strait in the south, or Queen Charlotte Strait in the north. At the southern end it flows north into Georgia Strait through the many passes and waterways of the Gulf Islands and the San Juans, or south into Puget Sound via Admiralty Inlet.

From the north it forces its way through the islands but is restricted to just four routes, each of which has extremely powerful currents depending on the tide state. These strong currents, naturally, develop whirlpools and overflows, standing waves, at their race. The four 'gates' are Seymour Narrows, Surge Narrows, Hole in the Wall, and Dent Rapids, and each of them lets out onto a different path through the islands.

The first three merge together near Chatham Point on Vancouver Island, and are generally known as the Discovery Passage Routes. Since Surge Narrows and Hole in the Wall are both quite narrow, they were never good commercial routes. But Seymour Narrows was an excellent route other than a large and dangerous underwater mountaintop in the narrows called Ripple Rock, and several dozen ships were wrecked there over the years. That caused the other route - the Cordero Channel Route - to be the most popular until the hazard was reduced by a huge explosion in 1958, the largest non-nuclear explosion ever created.

The Cordero Channel Route involved passing 3 to 5 rapids before merging into Johnstone Strait, and the traffic along this northern route sustained many small towns and outpost until suddenly the commercial boats were using the Discovery Passage route after 1958. The little towns mostly withered away. But the route, with its challenging series of rapids, remains popular amongst pleasure craft anxious to avoid the often boisterous winds of the eastern Johnstone Strait.

Making the passage from south to north (or, more accurately, east to west) is difficult timing-wise because the tides flood eastward, toward the basin, and ebb westward toward the Pacific. Each narrows forms rapids through most of every tide, with currents at race ranging from 7 to 14 knots meaning most boats can only pass through at or near the slack of the tide. Since the eastmost narrows reverse current after the western narrows, to pass all of them one must get quickly from the start to the finish.

The first three rapids are close together, and are often generally referred to as Yuculta Rapids, although accurately Yuculta Rapids is the first of the the three. There are three possible routes through the second rapids, the safest and most direct being Gillard Passage. There are two route through the third rapids, but the route to the south of Little Dent Island is much preferred. Only some 7 miles in length, passing this group of three in one tide slack is fairly easy, but to reach all five rapids is a distance of more than 20 miles takes planning.

The usual strategy is to arrive an hour early on a flood tide, and get through at least Yuculta Rapids before the slack. We arrived almost 2 hours early on a neap tide, in hopes of working through the first three rapids before the slack, but the current at Yuculta was still fierce so we jilled beneath the protection of Kelsey point for half an hour before challenging the current.

We crossed over to the Sonora Island side to catch the counter-current along that shore and were racing up toward Lion Rock and the confluence with the main current, which slapped our speed down to only a knot or two over the ground. We battled into Big Bay where the currents are felt throughout, but more gently, and took stock of Gillard Passage. It seemed clear enough, so we got as far up-current as we could before heading over toward it.

We were only just high enough to get into the Passage before being swept past its mouth, but once in we slowly slogged against the stream. There was a surprising amount of traffic, upstream boats rushing down with the last of the flood, and a big tug came barreling up from nowhere behind us and startled me. Once free of the pass the current dropped, but we were still a half hour early for Little Dent Rapids when we got to it. Getting past was no struggle, but I was looking forward to a favourable current.

It finally caught us as we were approaching Greene Point and its rapids, and we squirted through at just under 10 knots over the ground. The speed quickly dropped, but was still above hull speed as we raced on to Wellbore Passage and the Wellbore Whirlpool. We were more than a little tense as the time for ebb slack approached, and passed, and we were still not quite at the narrows. But our speed was picking up, which showed the current was still with us. We motored through doing 7 knots, 1.3 over our hull speed, despite being more than 15 minutes late according to the tide tables.

We didn't tempt fate further, and ducked into Forward Harbour, just past the narrows. It was a good day, and an amazing run - 47.2 nm in 9:40, an average speed of 4.9 nm per hour.

[newt]

Good job Amgine. Keep good notes on your voyage, you never know when you want to write a book about all your adventures!

[Amgine]

::wink:: Why would I blackmail myself?