Tuesday, June 6, 2017

Yaculta and Dent Rapids

4/17/2017 Yaculta and Dent Rapids

Our past trips north through southern BC have always been pretty direct runs north our south, and we have always gone via Seymour Narrows, Discovery Channel, and Johnstone Strait. This time we decided to take the more inland route and pass through Yaculta and Dent Rapids. These are some of the more treacherous rapids in the PWN with high currents, whirlpools, and other such things unsavory for boaters.

It’s essential that you transit within a narrow window around slack current. There is about a 30 minute transit time between the two rapids, so you need to decide whether to split the difference and hit one rapid 15 minutes early and the other 15 minutes late, or time one for slack and hit the other 30 minutes late or early. Since Dent is the more treacherous of the two, we opted to time Dent for slack current, and reach Yaculta 30 minutes early.

As is often the case, anticipation was the worst part of the trip. After lots of studying of current tables and charts, and consulting with friends who had been through before, we decided to anchor the night before our transit in Squirrel Cove on Cortes Island. An early departure the next morning would put us at Yaculta 30 minutes ahead of slack, and at Dent in time for the 9:00 or so slack current.

Planning the approach can be tricky too. Leading up to slack water there is of course current on the approach route – sometimes a lot of current. Our boat can only do about 9kts, so planning needs to account for any current against us. If we expect an average 2 kt current against us, then I need to plan the transit assuming 6-7 kts of actual headway. If there is less current it’s no problem – I can just slow down. But if there is more current than expected, there is nothing I can do about it, and the result might be a late arrival and inability to transit the rapids.  So you need to err on the side of assuming slower rather than faster progress.

If the current is with us, then I typically plan around 8-9 kts of total speed including the current. That way, if there is less current, I can still make 8-9 kts, and if there is more I can just slow down, or even circle back if required.

With all this in mind, we planned our departure and got underway. But not long into the trip, I started to worry that I had messed something up because instead of a favorable current sweeping us towards Yaculta, we had an opposing current and were not making the required speed to get there in time for slack. I had been warned that although the Canadian Hydro Service (CHS) chart tables were accurate, many other tide calculators were off by significant amounts – enough to miscalculate a safe transit. Another common mistake with tide tables is mixing up daylight and standard times. Some charts do the conversion for you, and others don’t. All these questions were running through my mind as we chugged along at flank speed trying to make progress against an opposing current when I was expecting a favorable current.  It was looking like our arrival time was going to be way off.

Fortunately, the problem wasn't as bad as I feared. The initial channel that we were in had current flowing against us, but as soon as we turned into the channel leading to Dent, the current shifted around as expected and we were back on track for a slack arrival.  Phew.  Dodged that one.

Passing through at slack water you might wonder what all the fuss is about. But just go look for Youtube videos of Dent Rapids and you’ll see that the fuss is well justified.

We passed through Yaculta with favorable but safe current, and 30 minutes later through Dent with nearly slack current.  From there, we had building current behind us pushing us along.  And it was early in the day (maybe 10:00) so we pushed on.

Next up were the Greene Point Rapids.  We hit them at near peak current, but it's a much larger area and safe to transit with higher current.  Once through Greene Point, we were in Chancellor Channel and would soon face a decision point.  We could remain out of Johnstone Strait and head for Wellbore Channel and stay the night somewhere in that area, or go into Johnstone Strait and head for Port McNeill.

We decided we would proceed based on the conditions in Johnstone.  If conditions were good, we would jump into Johnstone and make a run all the way to Port McNeill.  As we approached, I saw a boat maybe 10 miles ahead of us called Drumbeat, and they were now out in the part of Johnstone that is usually the worst, so I hailed them on the radio to see what conditions were like.  Where we were in Chancellor was dead calm.  Drumbeat confirmed that Johnstone was calm too, so we went for it.

The run down Johnstone was excellent, but as we started to reach the mouth and approach Alert Bay and Port McNeill beyond that, the wind started to kick up.  It's common for the winds to pick up in the afternoon, and this seems particularly acute around Port McNeill.  Once before we arrived in 20-30 kts winds and had a hard time getting docked.  This time was only slightly better.

The further in the docks you can get in Port McNeill, the better the protection there is.  At the outer most docks, it can be pretty exposed.  This time there were a couple of slips in pretty far that were available, and I thought the wind would be on our nose once I got turned into the slip.  But as we got in, the wind must have been channeling in some way because I found it holding us off the dock, and no matter how much I ran the thrusters I just couldn't get close enough to the dock to get a line one.  So we gave up on that and pulled around the other side of the docks to a side tie where there was a lot more room, and more importantly where we were not totally side to the wind.  This time, with a little effort and some help from the captain of Drumbeat, we were able to get tied up securely.

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