Selecting the ideal swim windows for Juan de Fuca x 2 has been challenging. The first things I had to consider was water and air temperatures. Luckily there is a fantastic buoy right in the middle of the strait that collects temperature information. The NDBC Station 46088 (LLNR 16337) – NEW DUNGENESS – 17 NM NE of Port collects both water and air temperatures 365 days a year, 24 hours a day, every 30 minutes. By looking at the data from 2016 and previous years the swim month becomes clear. By August, the water temperature has warmed up to a cozy 11-12 celsius and the air temperature is is between 14 and 18 celsius in the day and drops to 11 to 12 at night. There is still plenty of daylight to warm my back while I am swimming.
The next step was to look at water movement, both tide an current. There are a lot of challenging currents in the strait, so much so that I was stuck just outside of Victoria in a bit of hamster’s water wheel for about an hour before I B-lined it into Ogden Point. There’s a great website that shows the tide/current movement in the strait by day throughout the year. The charts show 24 hour periods. By combining each visual with a graphics tool into one very very very long chart I could clearly see the dates that offered periods with less than 2 knot currents over a 24 – 36 hour period. I selected about 10 dates from the chart and then sent them to my pilot Gordon Higgins for final date selection.
Here’s a sample of what the combined chart looks like. The big dips in the green are days that are not ideal as the current is moving too quickly. I also had to look at how many hours each of the dips are and consider where in the water I would be. The brown bumps represent water flowing in the opposite direction. The timing of where I am on the dips and bumps can be the difference between me swimming in one spot for 5 hours or making it across the strait in 10. Thank goodness Gordon is overseeing final date selection as at can be fairly complex on a 24 hour swim.
Here’s a look at the final days Gordon has recommended. He is quite optimistic with how quickly I will cross, but as I learned from last year, with the help of a good current one can move a lot faster than they think. The purple boxes in the diagram represent the window and the vertical lines in the middle are when I am expected to reach the Canada/US border, Dungenees Spit, and then the US Canada Border.
Aug 1 – start 11:30am, arrive at spit slack water 9:30pm (10hrs later), back to Ogden Point 8:30am following day (11hrs later).
Aug 2 – start at 12noon, arrive at spit slack water 10:00m, back to Ogden Point 9am following day 11 hrs later.
Aug 18 – start 3am, arrive spit 1pm, back to Ogden Point midnight 11 hrs later.
Sept 1 – start 1am, arrive spit 10am, back to Ogden Point 9pm 11 hours later.
Now that I have the dates I can work backwards and start configuring my training plan. I will need to spend a bit more time in the water this year including at night!