Fluke: it is a drift fishery, so it is a wind and tide problem

Fluke fishing is really drift-speed fishing. Everything else is detail.

Species guide - Paralichthys dentatus

Fluke carry the highest tide weighting of any species in this model - 42% tide, 18% pressure, 18% wind, 12% moon, 10% light - and the reason is mechanical rather than biological. Summer flounder are ambush predators that lie buried on the bottom waiting for something to pass overhead. You catch them by moving a bait past a lot of them. That means drifting, and drifting means current.

Drift speed is the whole game

There is a fairly narrow band of drift speed where fluke fishing works, and most bad fluke trips are bad because the boat was outside it.

• Too slow (under about half a knot) - your bait sits in one place, you cover no ground, and you are effectively fishing a very small patch of sand for fish that are spread over acres of it. Dead slack water is dead fluke fishing.
• About right (roughly one to one and a half knots) - the bucktail bounces, the bait swims, and you cover enough bottom to find the fish that are feeding.
• Too fast (over two knots) - you cannot hold bottom without absurd weight, the bait skips past too quickly to be eaten, and you spend the drift letting line out.

This is why the score peaks in the middle of the tide and falls off at both slack and peak flow, and it is why fluke is the species where reading the shape of the tide curve pays off most directly.

Wind against tide: the trip killer

The single most useful thing to understand about fluke fishing is what happens when wind and current oppose each other.

Wind with the tide pushes the boat along in the same direction the water is moving. The boat and the water travel together, your line stays reasonably vertical, and you can feel the bottom. This is the good case, and it can even rescue a weak tide.

Wind against the tide is where trips die. The boat gets pushed one way while the water moves the other. Your line streams off at an angle, you need progressively more lead to touch bottom, and you lose all feel for what your bait is doing. The same 12 mph that made a lovely drift yesterday makes today unfishable because the tide is running the other way.

The forecast on this site gives you wind direction in the stat strip and the tide curve in the panel below it. Comparing those two before you go is the highest-value thirty seconds of fluke preparation available.

Where they sit

Fluke are not scattered evenly across the sand. They set up where moving water delivers food to them, which means edges:

• Channel edges - the slope where a channel meets a flat. Fish sit on the lip and take what the current sweeps over.
• Sand-to-mud transitions and any change in bottom type.
• Inlets on the moving tide, especially the drop.
• Around structure rather than in it - the sand adjacent to a wreck or reef often holds the bigger fish.
• Drop-offs and humps where current accelerates.

The larger fish - the ones people call doormats - tend to hold on the more defined structure and in slightly deeper water than the pack of shorts.

Light, pressure and temperature

Fluke get a low-light multiplier of 0.85, meaning dawn and dusk are very slightly less useful than for most species. They hunt by sight from the bottom, and a bright day on clean sand is perfectly good fluke weather. A midday trip on a good tide beats a dawn trip on slack water, which is not something you can say about many fisheries.

Pressure carries 18% - the usual pre-frontal advantage applies but is swamped by tide. Water temperature drives the season rather than the day: fluke move inshore as the water warms through spring, spread into bays and inlets through summer, and pull back offshore as it cools in autumn. The sea surface temperature reading is most useful at the shoulders of the season for judging whether fish have arrived or gone.

A workable fluke plan

1. Find the days where the tide curve is steepest during daylight.
2. Check the wind direction against the direction that tide will run in your spot. If they oppose, look at another day or another location.
3. Favour moderate tides over big spring tides unless you carry a drift sock.
4. Start on an edge rather than in open sand, and pay attention to which part of each drift actually produces - then repeat that stretch instead of the whole drift.

As with every species here, check your state's current size limits, bag limits and open season before you go. Summer flounder regulations are revised frequently and differ sharply between neighbouring states.