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Writer's pictureJuliane Bell

Tides and Currents 101

Understanding tides and currents is essential for sea kayaking. Tides, the regular rise and fall of sea levels, are caused by the gravitational pull of the moon and the sun. Currents are created by the tide changes flowing through constrictions in ocean channels.


Here’s a guide to help you interpret tides effectively:


  • Know the Tide Cycle: Tides follow a predictable cycle. There are high tides, where the water level is at its highest, and low tides, where it is at its lowest. What happens in between is equally as important.

  • Use Tide Tables and Charts: Tide tables and charts are essential tools for kayakers. They provide detailed information on the timing and height of high and low tides for specific locations. These tables can be found online, through the Canadian Hydrographic Service's Canadian Tide and Current Tables, in local newspapers, or through dedicated apps. Make sure to consult them before your trip to plan your launch and landing times.


When paddling in the Comox Valley area, we recommend the following website:


When launching from Comox Valley Kayaks, the tides must be above 2.5 m for the full duration of your paddle.


  • Plan Your Route: Consider the direction and strength of tidal currents when planning your route. Kayaking with the tide can make paddling easier and more enjoyable, while paddling against the tide can be challenging and exhausting. Always factor in the tidal flow to ensure a smooth journey. 

  • Be Aware of Hazards: Changing tides can expose or cover hazards such as rocks, sandbars, and currents. At low tide, previously submerged obstacles may become visible, while high tide can cover safe landing spots. Stay vigilant and adjust your route accordingly.


Did You Know? 


  • Spring Tides: Occur during full and new moons when the sun, moon, and Earth are aligned. These tides have a higher high tide and a lower low tide, leading to stronger currents.

  • Neap Tides: Occur during the first and third quarters of the moon. The sun and moon are at right angles, resulting in a smaller difference between high and low tides and weaker currents.


Understanding the 50/90 Rule


The 50/90 Rule is a guideline to predict tidal current strength between turns.


Slack Water:

  • The period when the tide has stopped rising or falling and the water is still, occurring at high and low tide (or between ebb and flood currents as seen in parts of Eastern Vancouver Island).


The 50/90 Rule: Divides the six-hour period between slack water, peak current flow, and the next slack into six parts:


  1. Turn (or slack):

    • Flow: Water is still

    • Explanation: The current has stopped moving completely and is about to switch from flood to ebb or ebb to flood

  2. End of First Hour:

    • Flow: 50% of the maximum current speed.

    • Explanation: The current starts to build gradually.

  3. End of Second Hour:

    • Flow: 90% of the maximum current speed.

    • Explanation: The current strengthens noticeably.

  4. End of Third Hour:

    • Flow: Equal to the maximum current speed for that cycle.

    • Explanation: The current is at its strongest and most consistent.

  5. End of Fourth Hour:

    • Flow: 90% of the maximum current speed.

    • Explanation: The current has begun to slow down but is still moving quite quickly.

  6. End of Fifth Hour:

    • Flow: 50% of the maximum current speed.

    • Explanation: The current has slowed significantly.

  7. Turn (or slack):

    • Flow: Water is still

    • Explanation: The current has stopped moving completely and is about to switch from flood to ebb or ebb to flood


Understanding the 50/90 Rule helps kayakers plan their trips more effectively by anticipating the strength of tidal currents at different times.


Here’s how to use this rule:


  • Timing Your Paddle:

    • If you want to avoid strong currents, plan your paddling during the first and sixth hours after slack water, when the current is gentler.

    • To take advantage of a stronger current (for example, to help you travel faster in a particular direction), aim to paddle during the third and fourth hours when the current is at its maximum.


  • Route Planning:

    • Consider the direction of the tidal flow and the timing of your route. Paddling with the current can make your journey easier, while paddling against a strong current can be challenging and tiring.


By understanding and interpreting tides, you can enhance your sea kayaking experience, ensuring both safety and enjoyment on the water. 

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