Tides run big up here – especially around the spring tides (full and new moon). Especially as the moon nears its closet point of approach to the earth and that is happening now.
Canadian charts and tide tables are a bit different then the US and I actually like the system. The Canadian Hydrographic Charts – electronic and otherwise are based on the lowest astronomical tides of the year. Thus the published depths can be directly read as the lowest water you will see based on the lowest tide of the year. Thus, when the tide tables show a 0.0 tide, that translates to the lowest water of the year and corresponds to the depths you see published on the charts.
We are currently on a full moon and the other day we had a 0.0 tide. The top of the tide for the same day was over 18 feet and that rise occurred over a six hour period for an average of 3 feet per hour, but at mid tide, the rate is twice that or 6 feet an hour. That creates some very impressive effects in the narrow passes with the inrush and outrush of water from the larger bodies on either side.
Leaving Nimmo and proceeding thru several narrows that are typically benign, we had whirl pools and current flows of up to 4 knots. Places like Devil’s Hole, Whirlpool, Green and the other rapids that must be transited if one wishes to avoid Johnstone Strait would have been impassable to the point of being suicidal at anything other then slack water – and then you only have 10 or so minutes to work with.
Areas like the Seymour Narrows have current races that run at up to 16 knots and that is no place to be.
No good pictures at the moment but will put some up in another post.
Cheers