by Bruce Middleton, May 12, 2005

Flats 101, the means and understanding to catch bass in a prairie of grass…


In bass fishing the definition of a flat is " a large featureless area of the lake, usually in shallow water, that bass use to spawn on, feed on and live in." A flat is an under water tabletop that has very little if any topographical changes in it. That is to say the bottom doesn’t get deeper or shallower, it’s level. The whole flat area is something of an enigma to structure fishermen since this environment is lacking in structure. We are taught that structure holds bass in numbers, yet a structureless flat will likely hold 80 % of a lakes bass population. Enigma indeed! This is contrary to just about everything we’ve been taught about bass and their environment.

Flats are major feeding grounds for bass. These flats can be quite small or as massive as hundreds of acres. Approximately 80% of all the feeding done by bass takes place on these flats as born out by several University studies. Flats also provide 99% of the area used for spawning by bass. Flats are absolutely vital to bass reproduction and survival.

It is a well-established fact that bass are creatures of shallow cover. In the case of flats, vegetation provides the cover. In spring there is just the right amount of cover, in summer there is too much and in fall the bass seem to have left it. It’s not an easy place to fish because of the changing seasons and the growth habits of the vegetation. Knowing how to fish flats is a basic requirement for all bass anglers since this is where most of the bass live. A bass will strike a lure for four basic reasons, defense of territory, anger, reflex and hunger. If you can figure out why the last bass you caught struck your lure, you can use that knowledge to your advantage in formulating a tactic to get other bass to strike that same lure for the same reason.

There is no good or bad time to fish a flat, anytime is a good time. Now if you’re talking about a wider time frame, spring is a better time than summer and fall is the best time because the bass are schooled up at the edges of the flat and make a prime target for jerk baits and crank baits. Winter, when the bass are in deep water, is the only time a flat will not produce. In spring bass will be spawning in the shallower parts of the flats, in summer they will in the middle of the flat and in fall the bass will be migrating all over the flat in search of food, fattening up in preparation for winter. The migratory habits of bass make them easy to understand and a thorough knowledge of their habits is a resource not to be overlooked. The more you know about the bass, his likes, dislikes, habits, haunts, feeding behavior and movements, the better your chances of catching one are. Knowledge is prerequisite to everything.

Other sub-structure features to watch for on the depth finder/fish finder/electronics are such things as ditches, stumps rock piles, logs and other such things that are not readily seen from the surface. These underwater magnets draw bass in from all around as they provide a second form of cover. Any combination of cover features is better than a single feature. Bass will even orient to single rock on the bottom if it is the same size or bigger than they are. Anything that breaks up the monotony of the flat is a bass-attracting feature. A hump of a foot is all that is needed is some cases.

The presence of baitfish is probably the biggest draw of all for bass. If a flat has small glue gill, perch or other prey fish, you’re going to find bass in the area. But if the prey fish are not in the flat, the numbers of bass in the area falls dramatically. Crawfish in a flat like prey fish increase the likely hood of bass being on the flat. These mudbugs make up a large part of a bass’s diet. They are slow, easy to catch and fairly nutritious. But crawfish alone are poor fare for a bass and they will eventually move out in search of prey fish. The health of a flat depends on so many different things. The chain of life and predator and prey balances are easily disrupted. Thank goodness for the local B.A.S.S. chapters and the states fish and game departments and the efforts they put into making bass fishing what it is today. Great!

A couple of temporary conditions affect a flats appeal to bass. Wind causes ripples to form on the surface of the water and this ripple makes the bass fell safer. It protects them from predators like Osprey and Eagles. Bass are much more spooky in calm flat water than in rippled water. The wind also pushes prey fish from the deeper water into the shallows where the bass lie in ambush.

Rising and falling water levels is another temporary feature that affect the flats by changing the depth of the water and in may cases the clarity of the water. Heavy rains, raise the water levels and also introduces a lot of muddy water into the main body of water. Some temperature changes happen but the water levels and color changes are the most prominent. Rising and falling water levels also induce currents in the lake or impound. Currents of water moving over the flat brings introduce fresh oxygen, bait fish and insects. All these features turn on the bass and bass fishing suddenly becomes very good while these conditions last.

Before attempting particular seasonal options, lets start with some generalities. A good flat should be 2 to 10 feet deep. The most productive flats are 6 feet deep or shallower. You should start from the outside edge of the flat and fan cast 180 degrees all around the front of the boat as you move towards the shore. Make several casts at any irregularities on the flat, like a stump or other piece of structure, to insure it is covered well. When you can cast almost to shore, turn the boat and head back out to the edge, continuing to fan cast but not covering the same ground. Set up a pattern with the boat to cover as much of the flat as possible. On a really massive flat, say one that is several hundred acres, use a zigzag pattern with the boat and space the back and forth pattern wide apart so you can sample as much water as possible. This is referred to as running and gunning for bass.

Time on the water has no substitute. You can read this article and a hundred more about the same subject but until you actually get into a boat and go out and fish a hundred acre flat you will never have anything other than book smarts. One day of actual experience is worth more than a weeks worth of reading. It’s one thing to understand what’s involved in fishing a flat; it’s another to fish it in real time. On the water you will learn how to maximize your time, what looks good and what doesn’t. You’ll learn little details that will lead you to a greater understanding of the bass. You’ll know when to gun and run and when to slow down and work a spot extra hard. You’ll look at the sky and know what colors are going to work best that day and what baits to use. You’ll know to look for evidence of prey fish. In short you will become street wise, or in this case, flat wise. You will use your eyes and your electronics to their fullest potential.

Once you’ve decided to fish a flat, you drop the tolling motor and start to cover as much area as you can in as little time as possible. As stated before, fan casting and moving all the time and staying alert to any above or below the water surface structure that may require a few casts to cover it completely. You can catch bass off these structures or out in no-mans lands where nothing unusual appears. But if you go over that spot carefully, you will find something on the bottom that the bass was using for cover. Remember, it doesn’t have to be all that big.

Should you come across a dip in the bottom, try to determine if it just a pocket or an old creek channel or something in-between. The reason for this is obvious. If it runs for any distance, it will likely hold a great number of bass in it and along its edges. Mark the spot where you first found the dip and (casting all the while) follow it in both directions until you have found its limits. Any change in depth or contour can signal a place for bass to hold on.

If you are fishing a large flat and go a goodly distance and amount of time without a single strike, you may have stumbled into a dead zone. Don’t beat a dead horse. Move out of this area by several hundred feet and start over. Remember to mark you lake map as to the good and bad places to fish so the next time you return to the lake you know where to go and where to avoid. Lake maps take just a few moments to make while your fishing and provide you with invaluable information for years. And if you already have a lake map for that lake, keep it updated; again it will pay dividends in the future for you.

On the other side of the coin, if you hit an area of a flat that has turned hot, slow way down and slowly and methodically work the whole area. Don’t miss a single square foot of the bottom, cover it all. Change baits and lures in case the bass loose interest in one type of bait or vibration pattern. Work top waters, the mid water level and the bottom. Change the cadence of you retrieve, but keep working the area until it is completely exhausted before thinking of moving on. Remember too, to have a back-up rod ready with a worm or jig tied to it. This back-up rod has caught more bass than you can imagine. I’ve seen anglers on a half-mile flat spend all day working a 200-yard section, changing lures every now and then, and catching bass the whole time. Now that is an exciting day of bass fishing and one you’d not soon forget.

The mechanics of fishing a large flat are quite straightforward and five basic lures, with alterations, will cover 95% of all you’re needs. These five rigs are a crank bait, a spinner bait, a buzz bait, a jig and a worm. Now before we go any farther let me add that with alterations means that a buzz bait for instance can be substituted for another top water lure or a worm can be substituted for any other plastic. This will give you all the flexibility you need for personal choices too.

In springs cold waters during pre-spawn when shallow flats begin to warm up, it draws in bass. The initial move is not to spawn, that happens several weeks later after the water temperature is in the high 60’s or low 70’s. The early migrations into the shallows are for feeding. Bass follow prey fish and other forage into the shallows where they have moved because it is more comfortable for them. At this time bass feed heavily to build up reserves for the upcoming spawn and they are easily caught. A 4" worm rigged weightless, or as a jerk bait is a great bait to use at this time. Keep your offerings small at this time of year as big baits seldom work. Use finesse tactics as the bass are not yet overly aggressive and somewhat spooky.

After spawning you can bring out the entire arsenal of lures to go after the bass with. Spring is also a time of new vegetation growth. The aquatic growth is still low and won’t have too much trouble with hang-ups.

Post spawn, most fishermen agree, will be the time to use hard jerk baits to locate scattered fish, however, a Carolina rig will out fish them 3 to 1 once the fish have been located. 6-inch straight tail worms, French fries, tubes and big grubs work best.

In summer the rules change. Vegetation is at its thickest and shade is now a factor as a bass doesn’t have eyelids and can’t tolerate direct summer sunlight. Because flats are shallow your choices of lures will be limited again but this time to single hook rigs that don’t get hung up in the weeds. Plastics, jigs, spinner baits, buzz baits and top water lures are all good choices now. Crank baits are not the best choice with their treble hooks. But this is still a huge variety of lures and baits available to use. And look at the sky before you go fishing. When the sky is overcast the bass are usually more aggressive, so use spinner baits. Under clear skies bass go to cover so use worms, jigs and other plastics.

You cannot approach fishing a flat with one lure, one rod and one technique. All of the vegetation is not uniform in density. You won’t find a more complex situation if you tried. Now you can go along casting but eventually you will have to use a variety of techniques to fish the flat thoroughly from top to bottom. You will have to use top waters, buzz baits and floating plastics to cover the top. Jigs and Texas rigs to penetrate the interior, crank baits and spinner baits to cover the different depths around the edges and plastic frogs when things are so thick you can’t get a jig to plow threw the top of the weeds.

Fall, when the vegetation begins to die and the process of decay uses up most of the oxygen on the flat, the bass move out into deeper water. They still visit the flat during low light times of the day and at night to feed there but mostly they don’t stay long. . But bass do forage on the flat to fatten up for winter, and they are aggressive. Fish any green vegetation left.

This is the time to fish the deep edge of the flat, keeping the boat in the shallows and casting out into deeper water. Deep diving crank baits and slow rolling spinner baits are the two most used lures at this time. They have the ability to get down deep and search out the bass in these deeper waters while staying off the bottom.