Fishing Tides on the Grass Flats
Fish, especially fish in skinny water, are highly affected by the movement of the tide.
Flats are tidal zones; water moves onto the flats during incoming tides, pauses for a brief period during what's called High, or Flood tide, and then runs off the flats when the tide starts going out. Controlled by the moon, tides run very strong at certain times of the year, and much weaker at others. For the most part, however, water is moving in skinny water, making it skinnier when the tide goes out and fatter, or deeper, when the tide's coming in.
Fish – especially fish in skinny water – are highly affected by the movement of the tide. On flats, where water can literally run out and leave dry ground, fish have evolved to be part of the tide itself.
Besides their natural tendency to avoid getting stuck in shallow water, predators like the ones we're hunting in skinny water are highly evolved hunters, too. They don't waste a single wave of energy if they don't have to -- predators wait in places where bait is likely to come to them. If they do have to move to the bait, they try whenever possible to it – be it near the shoreline, in a hole on the flats, or near the edge of an oyster bar.
Different Tides on the Flats
The image below shows what's happening as the tide comes in (the first of the three graphics), sits for a while at flood, or high tide, and then starts its inexorable flow off the flats. The first (top) image shows how the fish (snook in this case, but it's all the same regardless of species) start to move up as the tide deepens the flat; they move all around the flats hunting when the water's at its deepest; and then – and this is an important "where the fish are" piece of advice – they wait for bait to wash off the flats as the tide goes out. This helps you determine where you – and your baits – should be at different phases of each tide you fish.
For sake of argument, let's assume you arrive at your Flat-of-Choice at 7 a.m., and the tide is just – just – beginning to come in; the flat is about as shallow as it's going to get today, and starting to fill up again.
You can't go all the way up onto the flat near the shoreline; there's no water there (usually, although the 'ditch' might be chock full of fish that you can't see or get to -- yet). You also know that the fish are at the same edge you are – probably underneath the boat – waiting for the water to fill in there. In fact, since fish pretty much feed all the time (just sometimes more than others) they're already interested in what's coming past.
This is the period known as Incoming Tides. The second rule of the day is that you should position your boat just outside the flats, so that your casts go alongside the actual drop-off itself, and onto the (now) increasingly deeper edges of the area. You can see that here. Now although we only show four casts, it's a good idea to move the boat north and south, or east and west, depending on the direction that edge is aligned. Fish the entire edge – unless you're catching fish in the first place you anchor, you should keep the boat moving along the edge, and you should spread out those casts as far and wide as possible.
Reposition your boat along this dropoff in the first few hours of incoming.
Three Different Places to Be
How long you should anchor in the outer-edge position depends on many factors, including the time of the year, where you are relative to the wind, and the exact nature of the flats you're fishing that day. As the tide floods, though, and that ditch, shoreline, oyster bars (if any), holes in the grass, and big hungry predators shopping around for lunch become available, move onto the flats.
Once there, drifting is usually as effective as anchoring. If you do anchor (to work the edges of the shoreline, for example, or to get out of the boat and wade to the ditch or around the flat), do it quietly. Flats are noisy to fish – they hear the slightest noise; keeping quiet as a mouse is critically important. This is particularly true with dropping things on the boat or hitting the hull or structure in any way; that banking sound carries through every bit of that flat, and will spook fish as quick as anything.
Tips about Tides on the Flats
- Fish could be wandering anywhere at the high tide. They're going to start moving the moment they feel the first whiff of an outgoing tide.
- Watch the holes and watch surface action, and watch for birds and watch for flashes of bright shiny fish-bodies. Also watch for shadows and dark movement.
- Longer casts with long, light tackle can let you access edges, mangroves, and ditches like this more effectively. Don't make noise!!!
- An hour before and an hour after high tides is the perfect time to drift the flats – more on that later when we talk about positioning your boat.
On the Drop-off When the Tide Goes Out
Now we're back to the secret that many amateur fisherpeople don't think about; if the flats hold fish on high tide, where do they go when the tide's going out?
They sit off the edge of the drop off, that's where. Like you saw in the picture showing the position of fish relative to tidal flow, you know that fish wait at the drop-off for the tide to flow off the flats and bring them tasty morsels. In this (relatively) zoomed out image, you can see that the boat is positioned (anchored, although drifting works fine here if you can drift along the edge of the drop-off itself). If the wind is pushing you over the drop off or away from it, anchor the boat – you'll get more fish.
The moment the tide turns from high to outgoing, fish move off the flats and wait for morsels of food to be swept into their big, hungry mouth-holes.