Book Extract – Underwater Angling by Paul Garner and Stuart Morgan

Underwater Angling by Paul Garner and Stuart Morgan promises to be a special book for it will reveal untold secrets of the underwater world. When Stu Walker and I made our Barbel Days and Ways films it rapidly became obvious to us that far too many so-called angling ‘experts’ made massive assumptions in their articles and books and pretty much chanted the mantra in earlier articles written by others. Without wishing to be too disrespectful they plainly hadn’t done their homework because our filmed experiments proved them to be hopelessly wrong. Sometimes it felt like we’d arrived at a flat earth society conference charged with a responsibility to tell them the earth was actually round.

Well, I haven’t seen the book yet but I’ve read many of the authors’ excellent articles in Improve Your Coarse Fishing to believe it will be something special. There’s nothing else around to compare it with and therefore it becomes the bible as we know it until somone comes up with contradictory evidence otherwise. And let me stress that small but important word – EVIDENCE. This book contains evidence and it’s backed by observation from two experienced and intelligent anglers. I know which party I’m putting my faith in being right. For now, here’s a sample chapter, published with the consent and approval of the authors. You’ll find details below on how you can obtain a copy.



I find stillwaters endlessly fascinating. Whilst at first appearance the calm surface of a lake, pond or reservoir might look a lot less dynamic and exciting than a river that is constantly moving, there is an awful lot going on below the surface of your average lake that we are never able to witness.

In this chapter I want to try and set the scene by looking at some of the factors that affect stillwaters, and how this can have an influence on the fish that live in them. To really do this subject justice would require a whole book of its own. Limnology (the study of stillwater environments) has a very long scientific history for anyone that wants to learn more, but I want to concentrate on just those factors that have a key effect on how as anglers we approach our fishing.

Types of stillwater

Stillwaters come in a multitude of different shapes and sizes, but all work in pretty much the same way, governed by the laws of physics, chemistry and biology. As coarse anglers we are mainly interested in man-made fisheries, be they gravel pits dug originally for their mineral deposits (but which just happen to make great fisheries), or commercial fisheries dug specifically for fishing. The way these lakes are made is actually pretty similar.

Throughout the later chapters of this book most of the underwater photography has been done in gravel pits and reservoirs, because these types of fisheries tend to have reasonable water clarity at certain times of the year. A lot of the methods though that we are looking at have been developed and are mainly used on commercial fisheries, often where the stocking levels are much higher and, as a result, the water is always murky. It would be great to be able to film carp feeding in commercials, but unfortunately the visibility is so low that we would see almost nothing.

In fact, filming fish in most stillwaters can be challenging to say the least! Algal blooms, coloured water and weed are just a few of the problems that we regularly encounter. On many occasions the action of the fish moving around and feeding is more than enough to stir up the swim so much that we can see virtually nothing. This isn’t just with big fish either, it is amazing how quickly a swim will become murky when a shoal of roach are feeding hard!

So although we have looked primarily at what happens in gravel pits; the results are likely to be pretty similar whatever type of stillwater you fish. In fact, having plenty of fish present to create murky water is perhaps one of the best ways we know to disguise your tackle and get more bites!

Lake topography

All lakes have features, from the simple slope of the margins and a tuft of overhanging grass, to a massive gravel bar, or island; all of these features will influence what is going on below the surface. The biggest single feature on any lake is the marginal slope. On some meres and natural lakes this can be a very gradual change in depth, but on most fisheries the margin slopes away steeply to create a sharp drop-off before tapering off. Because of wave action the marginal slope is normally quite stoney and silt free, with a lot of the finer material deposited at its base, depending upon the amount of wind that hits that bank.

Many lakes also have islands, and some may also have gravel bars, which are normally quite similar in their contours to the margins. Gravel pits may vary the most, but all of these features which produce a rapid change in depth are likely to have a different lake bed to the norm and are natural patrol routes for the fish that prefer to run along features, rather than go over them.

The other reason why the margins and other areas with variable depths can be so productive is that they enable us to intercept fish that are swimming in mid-water, allowing ledgered baits to be put right in front of the fish. I am certain that fish will seek out often a quite narrow depth band in which to hold and any areas that are in this depth band are likely to be investigated at some time or other.

Steep sided gravel bars, wooded islands, and densely overgrown margins also offer shade from the full strength of the sun. Small fish often seek out these areas as the lower light levels and structure give them an element of protection from predators, but because the suns rays are not as strong here these areas can be colder than more open areas of the lake.

Fish will exploit different depths at different times of the year and even at different times of the day and night, we will look at this more closely, and how you go about learning about the lakes topography in chapter 11. For now though it is important not to overlook any type of feature, as even the smallest variation in depth or amount of cover can be enough to attract fish, even the make-up of the lake bed can be extremely important.

The lake bed

Most anglers probably have in their mind an idea of what the lake bed looks like and what areas they think the fish are most likely to visit and feed over. I guess most of us think of the lake bed as being either mud, silt, gravel, or detritus, whereas in most cases the lake bed is actually made up of a mixture of all of these and more!

Let’s take the classic gravel spot as an example. Whilst we might think that this is made up of purely polished stones that create a great clean area for us to fish over, in most cases there will be all kinds of dead leaves, twigs and a fine layer of silt over the top of the gravel. Normally the only gravel spots that are really free from any kind of detritus are ones that have been fed on by fish for several weeks. Where the movement of the fish eventually washes all the sediment away. As they are visited by the fish regularly, you would imagine that these would be ideal spots to fish, but often the sheer cleanliness of the lake bed means that rigs and tackle are very easy for the fish to spot when they aren’t obscured.

Most often though we are faced with either a fine covering, or perhaps deeper silt, yet even this fine sediment is often not exactly what we might imagine. Deep silt made up of dead plant material; either weed or fallen leaves, it is often a very dark brown colour and has the foul smell of rotting vegetation that soon taints baits and end-tackle. This dark silt is produced when the layers of dead vegetation are put down faster than the bacteria present in the water can break it down. Although you can find plenty of invetebrates in the surface of this dark silt normally the lack of oxygen below the surface will mean that they cannot survive in great numbers. The one exception is often bloodworm, which thanks to their high concentration of haemoglobin (which give them their blood red colour) can survive in dense concentrations even when the oxygen levels are low.

Where the build up of dead matter is slower though the breakdown is much more thorough and you are left with a fine deposit of light brown coloured silt that is well oxygenated. This fine silt is often found covering most of the lake bed and because it contains plenty of oxygen and organic matter is home to a wide range of invetebrates that fish will feed upon.

Silt can vary greatly in its consistency, from a fine powder covering, to deep semi-fluid beds that bait and end-tackle sink into out of sight. Knowing exactly what you are faced with will determine the best tactics to use.

Occasionally you may also come across areas of clean clay, formed normally in gravel pits where the digger has stopped working a seam that contains little gravel, or on commercial fisheries where the clay is used to seal the lake bed. This hard-packed surface is normally very sticky, a light grey in colour and contains virtually no invertebrates because it is too dense for them to burrow into.

As we will see right through this book, the lake bed is often very different from what you might imagine, which can have an important bearing on your tactics, the colour of tackle that blends in the best, and how to approach a swim.

Water movement

Very rarely are stillwaters ever actually still! In fact, most lakes are almost constantly on the move, as the water circulates around the lake driven primarily by the wind. The stronger the wind the more movement you are going to generate, and this is most clearly seen on very large lakes. Where the coloured water created by waves stirring up the mud and silt on the down-wind bank will slowly spread out into the lake as the under-tow draws water back down the lake to redress the surface push of the wind.

In smaller lakes that are surrounded by tall trees, and those that are full of thick weedbeds, the action of the wind in creating undertow is severely reduced, particularly in the Summer months, whereas in gaps between bars and islands the sudden constriction of the flow can create a much faster current capable of scouring the lake bed clean.

A strong wind will also mix the water column vertically, helping oxygen dissolved at the water surface to find its way down into deeper water, and carbon dioixide and other gases to be released at the surface. A strong vertical mixing current caused by waves will also help to stabilise the temperature and remove any variation in temperature with depth. It is no coincidence that strong winds can trigger great fishing. Increasing oxygen levels, colouring up the water and eliminating temperature variations will all trigger fish to feed.


Fish are cold-blooded animals, so their body temperature roughly varies in line with the temperature of the water around them. This obviously has some major effects on how they behave through the course of a year, and even from day to day.

Sitting on the bank we are very much aware of the temperature of the air around us, but how often do we really know what the temperature is like out in the lake, and for that matter how it is changing? A lot of the time it is the changes and variations in water temperature that can have a major influence on what we catch. A lot of anglers will take a temperature reading in the margins; this is better than nothing, but can be quite misleading, as temperature can vary significantly around a lake and also at different depths.

So what are the factors that can affect water temperature around a lake? Lakes heat up in two ways. The main factor is heat induction from the surrounding land and air. As the environment warms up, so will a lake; this is normally quite a slow process that sees gradual changes in temperature. Much more rapid changes (perhaps as much as a few degrees) can occur in the space of a few hours through heat absorbed directly from the warmth of the sun’s rays.

Shallow areas will generally heat up and cool down faster than deeper water, because the volume of water is so much less in the shallows. So if you have a large shallow bay on a warm sunny day this is likely to be warmer than the main body of the lake. On a still day, when the wind isn’t mixing up the whole lake, the same can be said for the surface water over deeper areas. Because the surface water is in closer contact with the warm air above it and is also absorbing heat directly from the sun. In stilwaters you can often get a very marked variation in temperature in the late afternoon, with the surface water being noticeably warmer than the water below it. This is why fish will often come up to the surface to bask on a hot sunny day.

The type of lake bed can also affect how fast an area will warm up. Dark coloured silt absorbs a lot of the sun’s heat energy, and so warms up quicker than lighter coloured lake beds. Conversely, areas of the lake that are shaded by trees will often stay colder simply because they are in shadow for much of the day. Weedbeds can also trap heat from the sun, creating shaded cooler water underneath, whilst the weedbed itself warms up.

Another factor that can affect water temperature around a lake are streams, springs and upwellings where water enters the lake from the underlying land. Water entering from the ground beneath a lake is likely to be at a constant temperature right through the year, and so its effect depends upon the temperature of the lake. In the Summer underground water supplies are likely to be colder than the lake water, creating a distinct cold spot on the lake bed. In the Winter though the opposite can be true and the spring water will be warmer than the lake.

So what does all this mean for the angler? Well, as a general rule of thumb, fish are more likely to feed when the water temperature is either stable or warming up. Even a change in water temperature of 0.1 degree centigrade can be enough to affect the behaviour of the fish. So if you can’t visit the lake beforehand how do you know roughly what the water temperature is doing? Watching the weather the days leading up to a trip can give you a pointer. Warm days and nights, sunny conditions, and warm winds from the South and West are all likely to mean that the water temperature is rising, whilst with the opposite conditions the reverse may be true.

When you get to the lake think about which areas of the lake are going to warm up and which are going to stay more constant in temperature. If it is a chilly day, then look for the more stable areas where the fish are going to be more comfortable, but when conditions are more favourable perhaps the fish might be more willing to look for hot-spots.

There are really no hard and fast rules regarding water temperature, as every venue is different. I really do believe though that understanding how water temperatures vary and how this effects the fish is one of the massive gaps in our knowledge that remains and will be something that I look at more in coming years.

Weed and cover

If you fish well stocked commercial fisheries then weed is not something that is likely to trouble you too much. If, on the other hand, you fish gravel pits, then the chances are that weed, and finding gaps in which to fish, will be high on your list of priorities.

Aquatic plants come in many different shapes and sizes, and all can be a double-edged sword for the angler. Contrary to popular belief, weedbeds do not necessarily harbour great amounts of the invertebrates on which fish feed. In fact, a lake with very little weed, but a bed made up of well oxygenated silt and gravel can be much richer.

Dense weed though is a certain sign of a degree of nutrient enrichment that is the basis of the food pyramid which eventually trickles down to producing a fishery with plenty of natural food. Too much enrichment though can lead to invasive species like Canadian Pondweed taking over a fishery and crowding out many of our native aquatic plants. My favourite fisheries are those that have clear water and a diverse range of different plants, from lily pads and other floating leaved plants, to stonewort and hornwort and other submerged plants.

Where weed is perhaps most important, especially in lakes where it is not too rampant, is in providing cover for fish from predators. Here the type of plant is important. Species which are quite open with plenty of gaps between the stems are likely to hold a lot more fish than dense beds where the fish are limited to the outside. The species of fish is also very important. Tench are perhaps are best example of a species that is very well adapted to live in dense weed. In fact in their first few years of life baby tench very rarely stray away from very dense weed. At the other end of the spectrum, deep bodied bream are not lovers of dense weed.

Raking can be very effective in clearing a narrow band amongst dense weed to give you somewhere to fish, and although it can take a long time to clear even a narrow channel effectively, it is well worth trying if the lake is covered with very heavy weed growth. One thing to bear in mind though is that particularly in late Summer weed beds can often be almost hollow underneath, with great caves formed below what from above appears to be an unpenetrable mass of stems. Just like trees in a forest, each strand of weed will grow up towards the light and as the weedbed becomes more dense the light levels underneath will be reduced until the leaves at the bottom whither away. Some of the stems will flourish whilst others will die, leaving a dense mat at the surface with little remaining underneath. This can make raking a lot easier, and more effective than you might imagine.

Snags have a similar role of providing cover for fish as aquatic plants, but it is also interesting to note that this is not a great defence for predators, especially pike and perch, which both have a great camouflage pattern that allows them to lie in wait in snags and weedbeds until the moment is right to strike.

Overhead cover along the banks can also be a great fish attractor – especially in the Winter months when vast shoals of young roach and perch can be found tucked right in amongst the shadows, even when the water is not particularly deep. Overhead cover is probably a better defence against predatory birds than predatory fish, because the latter prefer the lower light levels to hunt in anyway.


I hope this chapter leaves you feeling that there are more questions than answers, as that is certainly how I feel! Lakes are complex environments where the fish are acutely aware of everything that is going on around them and can react instantly to their changing surroundings. Even pegs on commercial match fisheries that have been carefully dug with a consistent width, depth and bankside features are never completely the same, because the wind direction, angle of the sun, and other factors can have a massive effect on how the fish behave.

Learning and applying watercraft is never time wasted, try to think how the fish are going to behave and where they are likely to be and you are well on your way to catching them. If you can physically see the fish, or spot rolling or bubbling fish then so much the better. Sometimes though I am just left scratching my head, and you can’t expect to get it right all of the time!

Fancy A Copy?

For more information about Underwater Angling please visit Paul Garner’s web site where you will find examples of actual page layouts and have an opportunity to order copies direct from the authors. The book is 268 pages long spread over 26 chapters and retails at £24.99 plus £5.99 P&P