Tag Archives: Ripple Rock

Ripple Rock

Every year when the captain (my captain, that is) takes his commercial troller from Vancouver Island to the Queen Charlotte Islands on the northern coast of British Columbia (and back again), he has to go through a tight passage called Seymour Narrows.

Located just north of the town of Campbell River, this stretch of water was described by Captain George Vancouver as “one of the vilest stretches of water in the world.”

Whenever I have accompanied “my” captain through the narrows, I’ve nearly given myself an ulcer beforehand, as Seymour Narrows has such a terrible reputation. Yet each time, going through the passage has been a piece of cake, with calm waters. That’s how it should be, if you wait for slack water, between tides.

The passage through Seymour Narrows is now much safer thanks to the removal of the tops of Ripple Rock,  a submerged twin-peak mountain that lay just nine feet beneath the surface of Seymour Narrows. According to Wikipedia, it was a serious hazard to shipping, sinking 119 vessels and taking 114 lives.

In the case of the William J. Stewart, when it struck Ripple Rock  in 1944, I’m not aware of any loss of life, and the ship was beached and later restored. It was due to be scrapped in 2017.

On April 5, 1958, after twenty-seven months of tunnelling and engineering work, Ripple Rock was blown up with 1,375 tons of Nitramex 2H explosive. It was quite the project.  A 500-foot vertical shaft was built on Maud Island, and then a horizontal shaft of 2,370 feet  was drilled out to Ripple Rock. From that point, two vertical shafts were drilled up into the  peaks, with shafts for the placement of the explosives. Very advanced technology for 1958.

I think those columns of smoke are blowback  from the explosion, coming out through the drilled shafts.

The explosion spewed debris almost 1000 feet into the air falling on land on either side of the narrows.  After the blast, the two peaks were 13.7 m (45 ft) and 15.2 m (50 ft) underwater.

Some very smart engineers had the foresight to detonate the charge at a time when the tide was running its fastest, so the rocks  blown off the tops would not fall straight back down onto the peaks, but rather, be swished along beyond them.

Even after the top of Ripple Rock was removed, it remains a challenging route. In March 1981, the Star Philippine, a freighter, ran aground in the narrows.

When the captain was coming home from a summer of trolling, he took pictures of his navigation instruments as he went through Seymour Narrows quite close by Ripple Rock. The red triangular icon represents his boat as he is heading south, just past Ripple Rock. Arrows show the direction of the tidal flow at that time. You can see the depths of the peaks as 15.2 m, and 13.7 m.

In the monitor of the depth sounder below, you can see the twin peaks of the rock. The reading is taken on the far right where the scale is marked. This tells me that the boat has just passed the second of the peaks of what is left of Ripple Rock.

Even knowing that the rock has been topped, I still have a healthy respect for this stretch of water. The colour photos (near the beginning of this post) of the swirling eddies are recent, well after the explosion of Ripple Rock, so you can see that going through Seymour Narrows when the tide is running full is still not a good idea.

My preference is to stay on land whenever possible.