Southwestern BC has thousands of kilometres of coastline and some gorgeous beach trails but not all trails are passable at all tides. In this journal entry, I’ll explain how to read a tide table so you’ll be better able to safely navigate its glorious shore.
Select a Tide Table
Tides are the regular rise and fall of sea levels resulting from the Earth’s rotation and the gravitational pull of the Moon and Sun, which vary greatly among locations and over time, so it’s important to select the correct tide table.
Find Your Location
You need to select a tide table for the specific area in which you plan to hike. Tide tables for Canadian waters are produced by Fisheries & Oceans Canada and can be found on Tides.gc.ca. By clicking through a series of maps, you can find the one for your destination.
Unfortunately, selecting the appropriate table is not always easy. As an example, take Owen Point on the West Coast Trail, which is located in the Pacific Rim National Park on the west coast of Vancouver Island. An iconic backcountry adventure, the West Coast Trail stretches 75km from Port Renfrew in the south to Bamfield in the north and Owen Point is located about 8km out of Port Renfrew. For a visual tour of the Trail, see my journal entry 8 Days of Survival: Hiking the West Coast Trail.
Although there is a tide table available for Port Renfrew, to get accurate tidal information, backpackers on the West Coast Trail must use the tide table for Tofino instead, a town more than 120km away as the crow flies. The area around Owen Point is a difficult route with surge channels and boulders and the point itself is only passable at tides below 1.8m, so using the wrong table would be extremely dangerous.
The reason that the Tofino tide table more accurately represents the tides at Owen Point and along the West Coast Trail is that Port Renfrew is located at the end of a deep inlet, which dramatically alters its tides from the open coast around it.
If you are considering backpacking the West Coast Trail, don’t worry. Parks Canada will provide you with the correct Tofino tide table at orientation, and they’ll even help you understand it if you forget my steps.
Pick Your Date
You will also need to select a tide table for the specific time that you’re planning to hike. Because the movements of the Earth, Moon and Sun are predictable, tide height can be predicted for dates in the future.
As tide tables are only predictions and actual tides can be affected by other factors such as wind and weather, it’s also important to follow local bulletins such as the Government of Canada’s Wave Height Forecasts for the Pacific Waters.
Get to Know Your Tide Table
Tide tables show the high and low tides for a specific location over a week-long period. In Southwestern BC, there will be 2 low tides and 2 high tides per 24-hour and 50-minute period. This means that these are 6 hours and 12.5 minutes between low and high tides.
As an example, let’s look at the Tides.gc.ca tide table for Tofino for the week of September 27, 2021.
Government of Canada. “Tofino (08615).” Accessed Feb 1, 2022. https://tides.gc.ca/en/stations/08615/2021-09-27?tz=PDT#.
You will see that this tide table shows times (using a 24-hour clock) in Pacific Daylight Time (PDT). A 24-hour clock starts counting at midnight but does not restart counting at noon the way a 12-hour clock does. If you’re unfamiliar with a 24-hour clock, consider any hour less than 12 to be morning (eg, 05:41 is 5:41am) and subtract 12 from any hour greater than 12 and consider it afternoon (eg, 16:57 is 4:57pm).
As of 2021, Southwestern BC has a time change 2 times per year. We observe Pacific Standard Time (PST) from early November to mid-March and Pacific Daylight Time (PDT) from mid-March to early November. This means that if you’re using a tide table printed in PST (like the ones handed out in the West Coast Trail orientation), you’ll need to add an hour to the times listed. Don't worry though, Parks Canada will remind you in orientation and will have written "Add 1 hr" right on your table.
You will see 2 sections in the tide table. One shows times and heights (in both metres and feet) for high and low tides for the week, and the other shows tide heights (in metres) each hour for the week.
You’ll also notice the reference to “chart datum.” Chart datum is the level of water that the tide heights have been measured from. This reference depth is also used on navigational charts and has been selected so the water level will rarely fall below it. On most Canadian coastal charts, lower low water large tide (LLWLT) has been adopted as chart datum, which is the average of each year’s lowest tide over 19 years.
Use Your Tide Table
Let’s continue to use Owen Point on the West Coast Trail as an example. As I mentioned above, Owen Point can only be passed at tides below 1.8m (6ft). You’ll see these warnings on many detailed topographic maps, such as the Parks Canada map for the West Coast Trail provided to you during orientation or the many Coastal Hiking Maps by John Baldwin.
Parks Canada. West Coast Trail Map, Bamfield to Port Renfrew, Vancouver Island. [map]. Scale not given. Parks Canada, 2019.
Let’s imagine that I’m interested in hiking the West Coast Trail from south to north and I’m planning to camp at Thrasher Cove and pass Owen Point on my second morning on the trail to have time to hike to my next campsite by mid-afternoon.
It's safest to pass headlands on a falling tide.
Screenshots from Government of Canada. “Tofino (08615).” Accessed Sept 29, 2021. https://tides.gc.ca/en/stations/08615.
Let’s compare Tuesday 27 July 2021 to Tuesday 14 September 2021. According to the Tofino tide tables for each of these days (see my screenshots above), you’ll see that there were 2 low tides below 1.8m on July 27 (one at 9:55am and the other at 10:12pm) but there was only 1 below 1.8m on September 14, and that low tide occurred at 1:16am, which would have been an extraordinarily inconvenient and dangerous time to be crossing such challenging terrain!
To understand the tides more clearly, look at the predicted hourly heights for each day. You’ll see that on the morning of July 24, Owen Point was passable from 7am to 1pm but on the morning of September 14 it was only passable until 4am! It’s apparent from the tide tables that the beach route from Thrasher Cove to Camper Bay was possible on July 27 but that I would have had to take the island route if I had been hiking this stretch on September 14.
If you are planning to backpack the West Coast Trail, know that you’ll be given a tide table during your orientation for 8 days from your first day on the trail. It will likely be in PST so remember to add 1 hour to the times listed (don’t worry, they’ll remind you). Also, the table will show the times and heights for the high and low tides but not the predicted hourly heights, so if you want a better visualization of when you would be able to pass beach sections of the Trail, make sure to download in advance the tides.gc.ca tide table for Tofino for the exact dates you will be on the trail.
Southwestern BC has some incredibly spectacular and rugged coastline. The next time you’re planning a coastal hike, make sure to pick up an appropriate topographic map, download the necessary tide table, and check out any local wave conditions to safely navigate its undeniably beautiful shores.
With their pedometers, altimeters, and heart rate monitors, smartwatches are valuable tools for tracking fitness, but what if the battery in your smartwatch were to run out? If you are hiking in an area where safety is tide dependent, make sure to wear a mechanical watch so you’re not relying on your smartwatch’s relatively short battery life. If you simply can’t be without your smartwatch and those epic stats, consider wearing both.
For more information about tides and other coastal hazards in Southwestern BC including surge channels, rip currents and tsunamis, be sure to check out the Coast Smart website.
2 Responses
Great post! Thanks for sharing.
Thanks, Sheila. Really appreciate you taking the time to comment. Enjoy the trail!! 🌲🌊