Finding Fish on Grass Flats

Holes and shapes form on the bottom. What shapes, you might ask? The shape of shallow bottoms, that's what shape. While shape (holes, edges, slopes, wrecks and coral) might seem important offshore and not so important inshore where water's skinny, it's just as – maybe more – important in skinny water as it is in deeper, offshore waters.

The Shape of the Bottom

Shape means change, and change means bait. Bait means fish, and we're back to fishing where the fish are.

Rule #1: Fish Look for Structure Everywhere

Fish prefer shaped (un-flat) bottom conditions, even when they're feeding on the flats. That includes drops, holes, rocks, channels, oysters, patches of grass, something that changes the 'shape' of the bottom where they live.

A good example of the shape of the bottom can be seen when you're on a flat. Flats are defined as large areas of shallow water – ranging from 5 feet deep to 1 foot. Although we've caught fish in a foot of water, it's about the limit. If you put a five-pound redfish in 12 inches of water, he doesn't have to 'tail' (stick his back out of the water). It's out of the water all by itself even though his belly is scraping the bottom.

In general, the flats that are between 2 feet and 4 feet deep throughout are the one's you'll catch the most fish on. Remember that the typical tide in the Bay moves 2 feet either way – from a medium of, let's say three feet, it will be one foot deep on the shallowest (winter) and weakest tides and almost five feet deep when it floods (in the springtime) and gets its deepest and strongest tides.

The thing to remember about these holes you'll see on the flats is that they don't look deeper – they just look bare of grass, or empty (or filled with a weird dark log-looking thing with a big stripe on its side).

Let's look at a graphic (our favorite way to show you what we're talking about).

There are water columns in shallow water too. Remember, the deeper holes are shadowed and a little cooler than the water at the very surface.

Holes like the ones we describe here aren't the only form of structure you'll find on the bottom of apparently (at first) flat or level salt water fishing zones, either. There are oyster bars, small ridges, and grass.

Something else to think about when looking into, for, or around holes is that they can aid in your ability to see fish. Snook, redfish, trout, and other predators stand out if you're looking carefully (and have the right sunglasses, which we're going to talk about in a section all their own).

Another thing to consider when looking at holes is that schools of baitfish cross over them. Although you might not be seeing the entire school of big fat tasty (to Snook and man alike) sardines on the flats when you're looking over the grassy areas, the edges of a school of baitfish will stand out when the contrast between their dark backs and the lighter sandy holes jumps out at you.


Small baitfish like sardines as well as larger predators can both be seen easier as they pass over sandy holes and the contrast shows their shapes.

Both small baitfish like sardines as well as larger predators can both be seen easier as they pass over sandy holes and the contrast makes their shapes stand out.

Grass, Depth, and Other Structure on the Flats

Grass grows on some flats and not on others; at some times of the year and not in others. At the time we're writing this book, there's arguably as good a growth of grass in Tampa Bay as there has been for 20 years. A combination of more general environmental awareness – at state, local and individual levels – and the ban (we should say reduction, not ban) on gill netting in Florida waters has resulted in a healthier ecosystem all around.

There are a number of different grasses that grow in the bay and in shallow saltwater in general. Although each of them has their own Latin names, they're lumped into a general grass category known as Submerged Aquatic Vegetation, or SAV for short. Grass grows in different depths, and (depending on the tide, of course) different distances from the surface. In the flats near Tarpon Springs, for example (a town about 30 miles north of where we are in Tampa and on the Gulf Coast) you can easily find water that's six feet deep on average, and has a rug of grass two and three feet deep on the bottom of the rich, beautiful area. You'll also find grass that's only six inches tall growing in two feet of water that's just as productive as the deep and thick growth; it's all structure, food, and tidal movement when it comes down to it.

Not all flats that produce fish are thick with grass; you'll find them with patches here and there and large areas of bare sand. In spots like that, you're more likely to find the fish near the patches and not in the large open areas. There are bigger predators lurking around, you know, and snook aren't exactly stupid.

To best see how grass grows on the flats, lets' look at the flat from the side – like we looked at the holes a few pages back. We're going to attempt – wherever possible – to draw these illustrations so they help you understand what you're looking at when all you can see (for real) is the surface of the water, often impossible to see through.

On the left side of this drawing are the mangroves, and as you can see there's a small depression that runs along the edge underneath the vegetation. Although you won't always find such a fish-holding ditch running along the shoreline, you will if the tide moves well through the area and past the shore – there will still be water there. In other places the edge of the flat just gets shallower and shallower till it runs out from underneath the water.


Watch for patches of grass where the flat tapers off into deeper water.

The shape of the flat is apparent in both these images; the mangroves at the edge, the 'ditch' often caused by tidal movement along and under the mangroves (and prime fish-holding area); the flat itself complete with (slightly) deeper holes, an edge that moves deeper and stays deeper – even at the lowers of tides; and grass species different than the shallow variety that can just as likely hold bait and the predators that follow it.


This second image is the same thing from the top as above image.

Fishing the Flats and Edges

We've made a 'hole' in the water so you can see the sharp edges. Each of these edges represents depth changes. The big fat arrow in the middle shows that fish move in on higher tides, when the water's deeper near (and even under) the mangroves, and move towards and below the deeper edges when the tide is lower, and the water on the flats gets a little too skinny.

The Online Fisherman

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