How do Tidal Currents affect my sailing?

Tidal currents ebb and flow with the tide. The movement of the tide near the shoreline going up at high tide and dropping down at low tide create tidal currents. So like the tide, tidal currents are affected by the Earth, sun and the moon. We tend to only talk about the moon affecting the tide which is mainly because, as it is closer, it exerts a greater force. Tidal currents will increase and decrease depending on the phase of the moon. When it is a full moon or a new phase, currents will be stronger (spring currents), whereas when the moon is at 1st or 3rd quarter phases, currents will be weaker (neap currents).

Tidal currents are the strongest in areas with strong tides. Certain areas have bigger tidal currents than others. Those sailing around the English Channel would of course need to know about these currents, whereas someone sailing in the Mediterranean would not be severely affected. Inside the User Interface of TZ Navigator v3 and TZ Professional v3 you can easily display the direction of currents. In addition, by clicking on individual currents, you can find the speed and direction which change with the tide.

Tidal currents data overlay on the English Channel sea marine chart
This window pops up when you click on an individual tidal current. It provides you with a more detailed account of how the tidal current will change with time

A real requirement for anyone sailing is to know how best to avoid or benefit from the currents at their strongest time.

With the new TZ Navigator v3 and TZ Professional v3, it is possible to get an indication of the impact that Tidal Currents can have on your boat.

This exists thanks to an innovative feature, the Route Wizard, that pops up right after you finish creating a route. This tool makes it possible to set the parameters of the route so that the boat has the least travel time possible on a given day of departure. In this example let’s create a route in the English Channel and then see how the currents would affect the overall trip time.


Amongst other options, one great feature of the Route Wizard is that it lets you know the best departure time for a certain day. This is great because you not only save time, but fuel too.

Best departure time: use this option when you want your TIMEZERO software to select the best departure time based on the currents along the route (taking into account your average speed on all legs). It will look for the best departure time around the time you selected (+/- 12H).



Here we found that by leaving at 4:45pm instead of 9:45am, a total of 2 hours and 33 minutes will be saved. This lets you know how much of an impact tidal currents have on journeys within the English Channel.


By opening Route Detail, you will find specific information on the current direction and speed at a given location.


All in all, HR Tidal Currents charts allow you to make more accurate decisions and be safer when travelling near coastlines. For those who own a sailboat, you might even want to go further to modify your route and take advantage of or avoid tidal currents. When using the Weather Routing module, you can find the best route to get from A to B simply by clicking a button and a calculation will use tidal currents as well as wind as factors in finding the best route. So if you want to be as accurate as possible then this is a great addition to your quiver.

Current marine areas covered:

  • United Kingdom
  • Netherlands and Belgium
  • Channel
  • Southern England and French Atlantic coast
  • French Atlantic coast and Bay of Biscay
  • North Sea, German Bight, Skagerrak, Kattegat and Western Baltic
  • East Canada

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