Skull Cove: The name of our Bramham Island rock-rimmed anchorage was enough to prompt concern. The least depth of 11 feet overnight was worrisome, too. The scariest issue, however, turned out to be conflicting information on the best time to take my 42-foot Grand Banks through Nakwakto Rapids, where the maximum ebb current runs at a ferocious 14.5 knots. Get there at the wrong time in a 7-knot boat and we’d be in big trouble.
Nakwakto Rapids is a white-water gateway to a superb but lightly visited cruising area on the central mainland coast of British Columbia. Having safely navigated through the dangerous passage, boaters will enjoy exploring Seymour Inlet, Belize Inlet, and Nugent Sound, where snowy peaks rise far above the sea and waterfalls tumble hundreds of feet to the water.
I had been planning this adventure for months and based my schedule for passaging the rapids on current tables from the Canadian Hydrographic Service as published in a spiral-bound tide-and-current book called Ports and Passes. Firmly fixed in my head was June 18, 2011, the date of my planned passage, and 1257 hours, the time of slack ebb in the narrows that day.
After waking that morning I first checked to see if we still were floating. Satisfied, I brewed coffee and began reviewing the plan. I had been cruising for weeks with the aid of Coastal Explorer 2011, an intuitive and easy-to-understand navigation program by Rose Point Navigation Systems. Using it, I plotted the 4-mile run up Schooner Channel to the rapids and then clicked on “tidal currents” just to double check the time of slack water.
The graph popped up and I was dismayed to see it showed slack at 0957. Hey, I thought, we missed the bus.
Looking closely at the Coastal Explorer current graph, I noted the heading read: “Gordon Channel (based on Seymour Narrows, B.C., current).”
Gordon Channel was an immediate red flag. The channel is more than 15 miles west of Nakwakto Rapids, across Queen Charlotte Strait, and what happens there in open water has no bearing on the rapids that flow between the narrow gap between Harvell and Johnson Points on the British Columbia mainland.
The mention of Seymour Narrows thickened the fog of uncertainty. While some might think that sounded right, I need to emphasize that we were headed for Seymour Inlet, not Seymour Narrows, which is another notorious tidal rapids near Campbell River, B.C., roughly 100 miles to the south. I worried some boaters—possibly newcomers to coastal cruising and the geography of the area—might be reassured by catching the Seymour name in a quick read of the title on the Nakwakto chart and think “that is the name of the place we’re going, isn’t it?” If they accepted the time as valid and reached the rapids while the current was roaring they would be in grave danger. It’s probably a million-to-one risk that could happen. But it was a mistake we did not want to make.
Dave Wilshin, my crew for the exploration of the inlets, and I decided to ignore Coastal Explorer current data and stick with our original plan and the CHS timing. Being conservative, however, I launched my Nobeltec Admiral navigation software and found its timing of slack water at Nakwakto was precisely the same as that posted by the Canadian government. Two-to-one always wins.
Reassured, we moved out of Skull Cove at 1200 hours into Schooner Channel with the main ship’s computer displaying Coastal Explorer charts and a back-up laptop running Nobeltec charts and displaying current info. As we moved through Schooner Channel, dodging rocks, floating logs, and sand bars, Nobeltec counted down the time until slack and we could see the speed of the ebb current diminish, too, as we moved closer to the rapids.
Our stereo navigation delivered us to the rapids a few minutes before slack ebb and GPS indicated a current of only 1 knot as we motored through in calm water. It was an easy passage into a wonderful cruising area and we were satisfied that 1257 was the correct time.
This was my second misadventure with Coastal Explorer current displays. A year earlier, cruising southbound in Fitz Hugh Sound in northern British Columbia, I asked Coastal Explorer for current information and was surprised to see a reading from a station on a waterway several days to the north.
So, you ask, what’s wrong with Coastal Explorer?
First, unlike Nobeltec, Rose Point has not installed Canadian current and tide information in its navigation software because it objects to the fees and royalties charged by CHS. (Jeff Hummel, creator of the Rose Point program, said the fee is $50,000, plus a royalty of 20 to 30 percent on the sale of any product containing that data.) The information displayed by Coastal Explorer on my PC monitor was from one of a limited number of tide-and-current stations that are included in NOAA listings for the Canadian portion of the Inside Passage. Explorer grabbed information from the closest (Gordon Channel with its timing linked to Seymour Narrows) and displayed it at Nakwakto Rapids.
Back home, I asked Hummel to explain what happened. He did more than explain, he also announced that a free upgrade for Coastal Explorer will eliminate the problem. First, his explanation of the problem I encountered: “Coastal Explorer contains tide and tidal currents for discrete locations,” he said in an email message. “If you right mouse click on the chart and there is not a tidal current location for that exact spot then it will search for the nearest locations, even when the nearest station is far away.”
For example, in Puget Sound (near Seattle) there are many stations and the one chosen by the software usually is near the boat, he said. He offered another example: If you were in Lake Chelan (in central Washington State) and asked Coastal Explorer for current info, it would display data for a station at Chuckanut Bay, which is near Bellingham, a seaport in the northwest corner of the state.
In my case, Coastal Explorer found only a faraway station that unfortunately shared the Seymour name with the inlet we wished to explore. It didn’t confuse my crew for more than a second or two, but the potential for trouble is there and elsewhere on the Canadian section of the Inside Passage for users of Coastal Explorer. “Presumably others may have encountered the same misunderstanding of how the software works, but in eight years here I’ve never received a comment about this,” Hummel said.I think it is more a matter of unfilled expectations than a case of misunderstanding. Coastal Navigator is an excellent marine navigation system; it’s not too much to expect that all elements of it should be equally accurate and useful. A change in the software program would guarantee there would be no such confusion in the future.
As for the end of the problem: Hummel said Rose Point has released support for C-Map charts, which means that British Columbia tide-and-current data will become available as a no-cost program upgrade. “We now will have access to the data we need,” he said. Hooray! I say. While our incident at Nakwakto Rapids was a rare event involving widely separated stations sharing the same name, it strongly reinforced my view that we don’t take boats into strange waters with only one source of information aboard, even if it appears to be complete and accurate.
Today, experienced boaters will carry a backup laptop that holds the same navigation programs as the main ship’s computer. They will have printed tide and current tables, a calibrated compass, and U.S. and Canadian charts for every mile of waterway they intend to explore as well as spare GPS receivers.
