We head north tomorrow into some wild geography, and first we must transit the Narrows. Seymour Narrows is one big, mean place in the passage between the Discovery Islands and the Vancouver Island shore. The waterway is constricted here to less than half a mile in width, causing the ebb and flow of the tide to reach alarming speeds – up to 14 knots of current. This is sobering now, but must have been terrifying when Ripple Rock sat in the middle of the narrows. Ships often were swept onto Ripple Rock until the 1958 when, as the photo above shows, it was blown sky high by 2.75 million pounds of dynamite. You can watch footage of the explosion at this Canadian Broadcasting website.