Saturday, February 12, 2011

Summer Trip Planning - Canadian Rapids

As I continue planning my 2011 upcoast trip, it is important to consider the many tidal passes that you might have to navigate. A tidal pass is a narrow and relatively shallow passage that has a lot of current. At the peak of the current flow - ebb or flood - there are numerous water hazards which can dangerously affect your boat - whirlpools, boils (rising water), and overfalls (waterfalls & large standing waves). As a result, most tidal passes should only be navigated at slack to be safe. Slack is that very short time between flood and ebb, or ebb and flood where there is no current and lasts only minutes. Some slack periods last only moments. I remember once watching a stick slowly moving through Nakwakto Rapids in one direction, slowly come to a stop, and then reverse direction all in less than a minute. Less than an hour later the rapids were so bad that it would be dangerous for my boat the MV Independence to navigate.

When navigating a tidal pass at any time other than slack you need to know what your boat can do and what do in case of an emergency. Although rare, there have been incidents where a boat traversing a tidal rapid has been driven to shore, collided with other boats or objects, or worst of all - capsized! So timing your arrival to hit slack is important. That means knowing the currents leading up to slack, planning an appropriate anchorage, and knowing how fast your boat travels. If heading into current you don't make much way, and the current gets worse and worse. Once, I was actually going backwards - losing ground, while going forwards! Or worse yet, you get caught in the current which is going with you and you lose your steerage - scary.

The passes that I treat with great respect, that is I generally only travel through them at at slack (or near slack) are:
  • Dodd Narrows just S of Nanaimo. There are some overfalls and whirlpools, but the biggest concern is the amount of boat traffic through this narrow passage.
  • The Yuculta's (pronounced Yew-Caw-Tahs) - Yuculta, Gillard, and Dent rapids. There are boils, whirlpools, and very strong currents in these rapids. Boat traffic can be a concern.
  • Upper Rapids (Okisollo Channel). Large overfalls (>5' at times) and very strong currents.
  • Surge Narrows (Okisollo Channel). Narrow passage with very strong currents.
  • Skookumchuck Narrows (Sechelt Inlet). Large overfalls, very strong currents, boils and whirlpools.
  • Seymour Narrows (Discovery Passage). Boils, whirlpools, and very strong currents.
  • Nakwakto Rapids (Seymour & Belize Inlets). Boils, whirlpools, and very strong currents.

Other rapids that I respect but are willing to travel at any time because I have years of experience and knowledge with them are:

  • Malibu Rapids outside of Princess Louisa. Strong currents, some overfalls, navigation issues, and other boat traffic.
  • Greene Point Rapids (Cordero Channel). Strong currents, boils, and small whirlpools.
  • Whirlpool Rapids (Wellbore Channel). Strong currents, boils, and small whirlpools.
  • Chatham Channel. Currents, narrow channel, and shallow areas.
  • Lower Rapids (Okisollo Channel). Currents & some boils.

My strategy for all of these tidal passes is to approach them while the current is going against me, meet them at slack and then ride the current through on the other side of the pass. This is particularly so when traveling those tidal rapids in and around Desolation Sound. Because of heavy boat traffic and rough water I generally avoid Discovery Passage which is just N of Campbell River. Discovery Passage seems to really funnel the NW winds down through it. When the current is ebbing (going N) and there's a strong NW wind - it is a recipe for rough water that I absolutely avoid. The longer route is via the Yuculta's and upper Desolation Sound. Generally the NW winds don't enter these channels, and the scenery is so very nice. When traversing this route N I have a series of rapids to traverse - Yucultas, Greene Point, and Whirlpool. I time my arrival to the first rapid - Yuculta - when it is at the end of the flood. I then make Gillard right at slack, and ride the ebb through Dent, Greene Point, and Whirlpool Rapids getting a great "downhill" ride averaging well over 7+ knots.

When cruising S (again I avoid Discovery Passage because of the chance of rough seas and boat traffic), I generally travel through Whirlpool and Greene Point the day before and then go through the Yucultas separately. A trick I learned from fishing boat skippers when traveling S on your way to the Yucultas, is to travel as close as you can to the Sonora Island shore and ride the back eddies instead of plowing head-long into the current mid-channel. At times I am not more than 20' away from shore but the depth is more than 60'. I've passed boats traveling in mid-channel not doing more than 3-4 knots, while I'm riding the back eddies and traveling 7+ knots. Woo hoo!

Anchorages approaching the Yucultas are limited. When cruising N, you've got a great anchorage in Squirrel Cove (Cortes Island) which is about 20 nautical miles away - down Calm Channel and Lewis Channel. There are a few mediocre anchorages which are nearer - Florence Cove (Hole In The Wall), or Frances Bay (Raza Passage) which will do in settled weather. When cruising S, you can stay at Blind Channel Marina, Shoal Bay Marina, Cordero Lodge or anchor in Forward Harbor (Wellbore Channel) or Cordero Cove (near Greene Point Rapids).

For me cruising through these tidal passages makes for exciting and challenging fun. If done right, you won't even know the danger you passed through. For 2011 the date for me to travel through the Yuculta's are on July 24. I will raise anchor from Squirrel Cove at 8:30 AM, travel the 22 nm at an expected average speed of 5.5 knots putting me at Gillard Pass right about 12:45 PM - perfect. I will then ride through Dent with a push, down Cordero Channel with a push, and if I want - I haven't decided yet - go further through Greene Point and Whirlpool Rapids all with a good push. I'll save time and money (fuel).

4 comments:

Alfex said...

This is great information for us boaters heading North. Especially the info about using the back eddies to get around the mid channel current.

Unknown said...

From reading this post, it sounds like you try to make the transit from desolation sound north mostly in one day, meaning that you get up as far as Hardwicke Island?

Then I take it that you wait for the right time to pass through the one section of the Johnstone strait next day, and are then in the general cruising area?

Thanks,

Larry

cruiser said...

Larry,
No, we commonly have cruised through all three rapids and cruised up to anchor at Port Harvey, or Matilpi, or Burial Cove, or Cutter Cove, or Potts Lagoon.

We leave Squirrel Cove, try to hit the Yuculta's early and ride the ebb all the way to the cruising grounds. It's a bit of a long day but very doable.

Larry O'Keefe said...

Don-
Any thoughts on traveling south from somewhere around Cordero or Blind Channel into the strait and then via the "middle" route - Okisollo Channel around to Octopus Islands? Seems like a good alternative and the same distance as going via the back (Dents) route and then through Hole in the wall.

Thanks for the entries. They are a tremendous help for planning my first trip north.