Navigation Briefing

Navigators need to have a close knowledge of tidal streams and currents.

- Mike Broughton

Latest studies show just how multifarious even mid-ocean currents are. Closer to the coast, matters of fluid dynamics get more complex and it is important to be able to simplify what is happening and use tidal streams to our advantage.

When on the water, knowing what the tidal stream is doing right now is a start and it is easy for people to miss basic clues. every single time you see a buoy or lobster pot, take in the ‘free info’ it is offering on tidal stream. even if the tide is slack, it is useful to know. it takes a little time, but it’s useful to calibrate your eye to be able to look at the tidal stream flowing past a buoy and know the difference between, say, 1.5 knots and 2.5 knots of flow. For racers, every time you go to get your start transits next to the committee boat, remember to look down at the flow of water next to the anchored vessel.

Another way of gauging the tidal stream is to look at the way other boats are moving in comparison to their background. Watching how another yacht is sailing upwind relative to a distant shoreline can give you a vital clue. if she is seemingly crabbing sideways to windward when beating, then we have a windward-going tidal stream.