Tides, and Why You Should Pay Attention to Them.

Tides may be the single most powerful and influential phenomena affecting coastal waterways. So a basic understanding of how they work and more importantly, developing a habit of paying attention to the intersection between tidal movements and weather and how they affect the ocean environment is an essential part of living, working and playing on or in the water. Whether you are boating, swimming, surfing or fishing, tides play a big part in your ocean activities.

What are Tides?

Simply put, tides happen as the moon’s gravity pulls on Earth’s oceans, causing the water to bulge out unevenly around the globe. As the Earth rotates, different coastal features and islands move into and out of these bulges. We see the water rise as high tides as coastlines come into the bulges and recede as low tides as the earth rotates out of the bulges.

To a lesser extent, the sun’s gravity also pulls on the ocean. When the sun and moon line up, their pull combines and creates extra-high high tides and very low low tides. These are called spring tides. When the sun and moon pull in different directions, they produce neap tides, which have smaller differences between high and low water.

On the west coast of North America, the tides are usually mixed, meaning there are two high tides and two low tides each day. These tides are not all the same height. One high tide is often higher than the other, and one low tide is often lower.

The total range of any tidal fluctuation is also greatly affected by local geography, and it can be dramatic with changes in water levels of over 20 feet in certain areas on certain tides. And as this vast amount of water moves up and down around coastal features, such as points, channels, and islands, significant currents and water speeds can be generated.

The timing of tides follows the moon’s rhythm. And since the moon rises about 50 minutes later each day, and tide times shift in a similar way. So a high tide at 8 a.m. one day might be closer to 8:50 a.m. the next day.

Why Tides Matter

For Boating

For boaters, tidal currents and fluctuations can significantly affect basic navigation. They can alter not only the sea state, but also where you can go, when you can go, how fast you will get there and what routes are available at any given time. Different points, channels and islands can cause tidal currents to develop into significant whirlpools, eddies, and virtual rivers as water is squeezed through narrow openings, and some passages will even dry out and become unnavigable in low water. If tides are not considered when anchoring or going ashore, ebb tides can leave you high and dry, while flood tides can float you right off your anchor, or the beach you’ve pulled up on.

For Salmon Fishing

For salmon fishing, tides can also play a significant role on when and where fish are most likely to bite. The general wisdom on salmon fishing says that it is best to fish the slack tides - that is, the hour or so at which the tides are nearest their highest and lowest points. However, that is not always the case and tides can act in a wide variety of ways. Some points and bays might consistently fish better on a flooding tide, while others only a short distance away will be better on an ebb. And on some days, the exact opposite to what might be expected of a given spot at a given tide will also occur. Bottom line, it always pays to be aware of what the tide is doing at any given moment during your fishing day, and to pay close attention to the times and places where the fish become most active in relation to what the tide is doing at that time.

For Surfing

Tides can also significantly affect surf.  Reefs and rocks that are covered in high water can become exposed in low water which is obviously an important consideration. Short of that, however, the same 2 metre swell with 15 second period recorded on an offshore buoy will break differently when it hits the beach depending on the level of the tide. Again, knowing and paying attention to tides can change your day.

Tides have incredibly significant and highly variable influences on our interactions with the oceans. The good thing is, unlike the weather, tides are also one of the most predictable natural cycles on Earth. As sure as the sun will rise and set each day, the tides will continue to go up and down.

And a good tide app (of which there are many), can tell you precisely when they will occur, and how big they will be. I primarily use “Tide Charts” from 7th Gear. Its is easy to use and does not need an internet connection which is handy as I am often out of service.

As the old saying goes, “time and tide wait for no man.” So if you have anything to do with the ocean, it only makes sense to get with the tides, as they will be a major influence on your outcomes, whether you pay attention to them or not.