A spacious sand flat with patches of sparse shoal grass. The seagrass and numerous animal burrows indicate a "live" flat that should be inviting to bonefish and permit.

Each type of tide has its advantages. During spring tides, gamefish know they can access parts of the flat that are normally unreachable, so they are eager to move onto the flat once the tide begins to flood. But because the amount of time between high and low tides stays the same regardless of tide height, the permit, bonefish, snapper, or crevalle jack must cover a lot more ground in a limited amount of time. In the worst case, although the shallow sand flat is "live," it is too far from the safety of deep water to attract gamefish in all but the most extreme tides. In the best case, gamefish will flood the flat with the tide and feed aggressively as they move through. In general, because of the risk associated with traveling too far on a high spring tide, gamefish start to leave the shallows in the early part of the falling tide.

Gamefish are still keyed to the tides during the neap tides but tend not to venture as far onto the flat or to feed as aggressively on the rising tide. While this might seem like a negative, it's not, because gamefish are more likely to feed throughout the tidal cycle than to focus on the rising and early falling tides. This is especially true of bonefish and permit.

The one caveat to following the tides in your fishing is the weather. Specifically, atmospheric pressure and wind can affect water level more than the tides in much of the tropics, where the normal tidal range is minor. High pressure and strong offshore winds cause lower-than-expected high and low tides, whereas low pressure and onshore winds cause higher-than-expected water levels for both tides. Given the tuned-in nature of shallow-water gamefish, these weather changes can influence gamefish behavior much the same as spring and neap tides.

Tides and wind move water, which creates currents. Most of the time, it's true that you'll find gamefish on sand flats moving into the current, but take an occasional peek behind you as you wade a sand flat for that occasional fish that rides with the current.

A less obvious aspect of currents is that they affect water temperature. During warm times of year, the water on sand flats can become too warm for comfort for gamefish. Rather than abandon the food-rich flats for the season, gamefish use the currents to their advantage. Tidal currents carry cooler water from adjacent deeper areas onto the flats with the rising tide, and if the incoming tide is strong enough, gamefish will ride the cooler water onto the flat to feed. During colder seasons, the midday sun will heat the shallow water over the sand flats. As the tide rises and is warmed by the sun and by the sun-baked sand, gamefish move onto the flat to feed. When the sun-warmed water begins to depart the flat on a dropping tide, it's worth searching out channels that drain the flat. Gamefish holding at the ends of these channels get the benefit of intercepting prey that is washed off the flat, as well as the extra warmth of the solar-heated water.

So when coming up with a strategy for fly-fishing a sand flat, you need to consider tides, wind, atmospheric pressure, currents, and temperature. Whether you find fish or not, it is worth making notes of the conditions on the flat, and fishing the flat under different conditions. It won't take long for you to figure out the patterns of the fish. If you are traveling to an unknown area for just a couple days, take the time to figure out the local tides and weather conditions, and make your best guess on where the fishing conditions will be optimum.