On a perfect early June morning I set off from Totnes and swam to Torquay. It was a swim I’d always wanted to do.

Roo and Johan Prince watch the sea for tidal streamRoo and Johan Prince watch the sea for tidal stream

I’d planned it as a full day’s adventure experiencing the delights of the stunning river Dart into the fabulous South Devon coastline.

At over 35km it’s not a swim you can do without a fair bit of training but it’s not as impressive as it might sound as tidal stream can assist you for most of the way.

The reason I wanted to do this swim was not to test my swimming ability but to test my knowledge of tidal stream.

You can only complete this swim if you understand the tides and if you get it right, you can swim faster than an Olympic swimmer. Thankfully, I did and by the evening I swam into Torre Abbey Sands, assisted by mother nature for most of the way.

I want to explain tidal stream to you as it is often forgotten about when considering water safety.

This is because it is almost invisible to the naked eye and can be quite complicated. I promise I’ll try and keep it simple.

Water flows back and forth along our coast due to the tide and the tide effects vertical and horizontal motion of water.

Vertical motion can be witnessed at Paignton harbour, at high water the boats are all floating and at low, they are all sitting on the sand.

Horizontal motion or stream (flow) has more of an impact on your journey at sea. Stream or flow is what I was relying on to make my swim possible.

At times this stream was traveling at 3 knots (1 knot = 1.8km per hour) which gave me a natural motor of 5.5km per hour before I even started swimming!

Spring and neap tides have a considerable impact on stream. In a spring tide the water will flow faster due to the greater volume and slower in a neap.

For anybody wanting to go into coastal water, they should understand stream and how this can affect your safety on the water.

In Torbay, because it is a Bay, there is very little stream at certain times and areas.

In fact, the effects of convection currents from river outlets into the centre of the Bay can move the water more that the stream.

This changes dramatically around the two stream pinch points at the headlands of Hope’s Nose and Berry Head.

Water in these areas can be moving faster than the average swimmer or someone new to paddle boarding can paddle.

Next time you look at coastal water see if you can spot tidal stream.

There are a few ways of doing this, look for any turbulence on one side of the legs of piers, posts or buoys in the water.

Boats anchored out at sea will face the direction of the stream or throw a stick into the water and track which way it travels and how fast.

If you can see stream, think about how this may affect your activity and remember the water will flow in one direction for approximately six hours before changing to flow in the opposite direction for another six hours.

This flow doesn’t coincide with high and low water times for Torbay.

By checking the weather, you can also see what the wind is doing. If wind and stream are in the same direction the water will be flat, if against each other the sea state will change to rough.

If you are visiting the coast, always check the weather and tides. Also look for beach specific signage, speak to locals or check online to find out if the beach you are visiting has strong currents or stream.

Stream at headlands or estuary mouths can be considerably stronger. If in doubt about the conditions, don’t go out!