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Understanding Tides: The Rhythm of the Sea

When we head out on the water, whether for a short sail or a multi-day voyage, the tides are always part of the story. But what exactly causes tides, and why do they matter so much for sailors — and even for a simple day at the beach?

Tides are created by the gravitational pull between the Earth, the Moon, and the Sun. Although the Sun is far larger, the Moon is much closer to us, which makes its influence stronger. Roughly two-thirds of the tidal forces we experience are caused by the Moon, with the Sun accounting for the rest. Together, they create the daily rise and fall of sea levels that shape life on the coast.

 

Semi-Diurnal Tides: Two Highs, Two Lows

Here in British Columbia — especially around Vancouver Island and the Gulf Islands — we experience semi-diurnal tides.
That means we typically see two high tides and two low tides each day, at varying times and heights.
The two highs (and the two lows) aren’t always equal, but the pattern is pretty reliable once you get used to it.

Knowing the tides isn't just for sailors — it’s also key for planning a great beach day.
At low tide, sandy beaches and tidal pools are exposed, making them perfect for exploring. At high tide, though, that same beach might disappear almost completely underwater.
Timing matters.

 

Extreme Tides Around BC

Tidal ranges around here can be surprisingly big. In spots like Maple Bay or Deep Bay, it's not unusual to see a difference of 3 to 5 meters (10 to 16 feet) between low and high tide.
At certain times of year — like during spring tides (around full and new moons) — the range gets even more dramatic.
During neap tides (around quarter moons), the difference shrinks, making for much calmer changes.

If you're cruising, hiking, or even just planning a dockside lunch, tides are always worth keeping an eye on.

 

Why Tides Matter When You're on the Water

When we anchor out, it’s not just about how deep the water is when we drop the hook — it’s about how deep it’s going to get.
If you anchor at low tide without factoring in the rising tide, you might not leave enough anchor rode out.
A good rule is to set a scope (the ratio of anchor line to water depth) of at least 5:1, but always calculate it based on the highest tide you’ll encounter while you're anchored.

For example:
If you’re anchored in 3 meters of water at low tide, and you know the tide will rise another 3 meters overnight, your calculations need to be based on 6 meters, not 3.

Of course, this is just the beginning of what we dive into during our sailing courses — where we practice anchoring techniques hands-on in real conditions

The tides also shape our experience of wildlife.

• Seals love to haul out onto rocks during low tide.

• Birds flock to exposed tidal flats to feed.

• Tidal pools become little worlds of starfish, anemones, and crabs.

And of course, the tides influence how the ocean moves beneath us.
When the water’s shallower — like at low tide — waves tend to steepen and become choppier, especially if the wind is blowing against the direction of the swell.
At high tide, deeper water can smooth things out, making for a softer ride.

Understanding these patterns makes your time on the water not just safer — but more connected to the natural world around you.

Tides and Coastal Adventures

Even if you’re not sailing, tides are a big deal on land too.
Take the West Coast Trail on Vancouver Island, for example. Parts of the trail are only passable at low tide.
Get your timing wrong, and you could be stuck waiting for hours — or find yourself rerouted inland along tougher paths.

Even casual beach walks around Victoria, Sidney, or Salt Spring Island can be much easier (and safer) if you know what the tide’s doing.

If you want to check local tides before heading out, a great resource is tides.gc.ca – Victoria Harbor.

A Quick Trick: The Rule of Twelfths

There’s a simple rule sailors often use to estimate how fast the tide is rising or falling: the Rule of Twelfths.

Here’s the basic idea:

• In the first hour after low tide, the tide rises about 1/12 of the total tidal range.
• In the second hour, 2/12.
• In the third and fourth hours, 3/12 each (the fastest part).
• Then it slows again: 2/12 in the fifth hour, 1/12 in the sixth.

 

It’s not perfect math, but it’s a handy way to quickly judge whether you’re dealing with fast-moving water or a slower, gentler change.

 

Wrapping Up: Why It All Matters

Tides are one of the most fascinating — and important — forces we work with on the water.
They shape everything: where we anchor, when we move, what wildlife we see, and even how the sea feels under our hull.

Of course, tides and currents are closely connected.
Currents — the horizontal movement of water — are driven by tidal changes, but they’re a whole topic on their own.
(If you’re curious about that, keep an eye out — we’ll be posting soon about how to read and work with tidal currents too.)

At Faro Sailing, we believe that real seamanship comes from understanding the forces at work around you — not just handling the sails.
Have you ever planned a sailing trip, a beach day, or even a hike around the tides? It's a simple skill that can change the way you experience the coast.
If you're ready to dive deeper into coastal navigation, anchoring techniques, and everything that makes sailing safer and more rewarding, explore our hands-on sailing courses and take the next step toward building real confidence on the water.