Understanding undertow

Did you know that stillwaters, lakes, meres, estate lakes and even commercial fisheries are rarely absolutely still? When the wind blows strange things happen to the water underneath the surface...

Even the faintest breeze can have an affect on the lake itself because, like Newton once said, for every reaction there is an opposite reaction.

So, the wind blowing over the surface of any lake anywhere is bound to affect the water immediately underneath those moving air particles and that affect is to create water movement. In other words, the dreaded undertow.

Everone who has ever floatfished a stillwater when it's windy will have, at some point, suffered from the affect of undertow.... those times when your float willl not stay still and keeps drifting through the swim making presentation really awkward, but worse still, makes your bait move unnaturally.

Here's you'll find out a whole lot more about undertow, what happens under the water, how it works and what to do to beat it and carry on catching even in the strongest wind...


a Surface water movement direction

b Wind direction

c The water slams into the end of the lake and is returned along the lake bottom

d Frequently the strongest tow is found close in and weakens as you go further out

e On some waters, the wind pushes the water around the lake circles

f Undertow, most of the time, will generally return in the opposite direction to the wind

g Undertow direction


If you have tow moving in the opposite direction to wind, this is the ideal scenario as it makes it easier to keep that bait still. Surface water movement is counteracted by tow along the lake’s bottom, so if you put your shot in a bulk in this area it will hold steadily in the swim.


When the wind and tow are in the same direction you get presentation problems. With the extra ‘push’ your float will scurry through the swim far too quickly, providing poor presentation. You might pick off the odd fi sh with the bait moving, but you really need to slow that bait down and present it still. It really is important to do this and having line on the bottom can secure your bait.


Undertow explained

Imagine you are pole fishing on a lake and your float is moving against the direction the wind is going. What’s going on here, then? (diagram, left) Well, it’s the undertow! When you have wind blowing against the lake this encourages the surface water to run in a particular direction. And then, when it reaches the far bank, currents are transferred to the bottom, so what happens is that the currents go back in a reverse direction, circulating water within the lake.

Remember, it’s not always fixed either, with currents and tow moving in different ways, sometimes even in circular fashion like a tumble dryer. And before all this talk of circulating currents puts you off, remember that undertow is a good thing, as water movement introduces oxygen into the water, encouraging fish to feed.

Beating undertow when fishing a waggler...

Although this is near impossible, there are a few things you can do to slow your rig right down whenever fishing in a strong wind and equally strong undertow...

Sinking your mainline between float and rod tip helps. To do this either cast further than you require, dip the rod tip under the water and wind the rig back really quickly to force the line under the surface. Alternatively, cast out, straighten your line, dip the rod tip right under the surface and strike the rod upwards quite sharply.

Using a very long waggler helps too as this ensures that your line is positioned further under the surface.

Fishing overdepth can slow your float down dramatically too, but choose your bait wisely as heavy baits can become snagged on underwater blanket weed. One of the best baits is a single caster, set so that the hook is worked right inside the bait, ensuring that the hook point doesn't show.

Anchoring the rig to the lake bed also helps. Fish overdepth and add a No8 or two onto the hooklength so that the shot drags along the bottom, slowing the passage of the float down. To do this correctly you'll need to use a straight peacock waggler as this will have enough buoyancy in the tip to keep the float above water when the shot trundle along the bottom.

If all else fails...

Get your feeder rod out and start legering instead!