Cracking the Tidal Code

Once you understand this eternal cycle, you can consistently predict fish activityand increase your coastal fishing success.

Field & Stream Online Editors

The ebb and flow of the tides influence how fish feed and move, and a fisherman who understands these relationships will be more successful than one who does not. The height (also called "stage") of the tide is not the only factor that affects your coastal fishing. Fish also react to the currents created by these tides.

You'll have the most success fishing the tides when you understand that they are instruments of repetition; if you find good action in a given area at a particular stage of the tide, chances are you can go back to that same spot a day or two later, or even the following week or month, and as long as the tidal situation is identical, your chances of scoring again are very good. You can even extrapolate that same information for a year ahead of time with the same results.

Of course, external forces can impact this consistency. If the wind blows too hard from an unfavorable direction, it can make the tide rise or fall faster or slower. To a lesser extent, changes in barometric pressure also affect tidal swings. And the time of year is important too, especially because it causes changes in water temperature.

Springs and Neaps
Tides are caused by gravitational forces pulling on the earth's surface from the moon and the sun, although lunar forces have more effect because of the moon's proximity to the earth. While these forces pull on all the earth's surface, only the flexible ocean yields to the force. The ocean forms a bulge on the side of the planet facing the moon, while the earth's centripetal force forms another bulge on the opposite side of the planet. These bulges represent the high tides, and this explains why the tides rise and fall twice a day.

During the two quarter moon phases each month, the lunar and solar forces are pulling at a right angle to each other, canceling each other out to a certain extent and creating a smaller water bulge. These quarter moon tides are known as "neap tides" and have a much smaller range (lower highs and higher lows).

Tides repeat themselves according to the 281¿¿2-day lunar cycle, not in monthly increments. But it's a fair rule of thumb that if you had a falling tide in your favorite fishing spot on a Saturday morning, then it would be roughly the same two weeks later.

Tidal currents
Tidal currents play a dominant role when fishing in locations where gamefish use the currents' direction and speed as a means of locating food. Inlets, narrows, coastal river mouths, and estuaries are prime examples. But you must remember that changes in tidal currents are not usually simultaneous with changes in tidal height. There is often a lag, which can be as much as two to four hours!

For example, in a narrow inlet or opening with a large bay behind it the tidal current can still be running out at a fast clip even though the tide has been rising for an hour or two. Or, water can continue moving into the inlet long after the tide has peaked in height and is actually falling. Tidal current lag is usually greater during spring tides and smaller during neaps.

Tides also affect fishing along river mouths. If the river's natural current is strong enough, there may be little or no in-flowing tidal current with the rising tide. Or it might flow in slowly during spring tides and not at all during neaps. Anadromous fish returning to their natal rivers depend upon the outpouring water of the ebbing tide to bring them the scent of their destination, but they still may only enter the river as the tide floods, especially if the mouth is shallow. This is typical of salmon and sea-run trout.

Open Beach and Flats
Generally, tidal currents are weaker along an open stretch of beach or shoreline me examples. But you must remember that changes in tidal currents are not usually simultaneous with changes in tidal height. There is often a lag, which can be as much as two to four hours!

For example, in a narrow inlet or opening with a large bay behind it the tidal current can still be running out at a fast clip even though the tide has been rising for an hour or two. Or, water can continue moving into the inlet long after the tide has peaked in height and is actually falling. Tidal current lag is usually greater during spring tides and smaller during neaps.

Tides also affect fishing along river mouths. If the river's natural current is strong enough, there may be little or no in-flowing tidal current with the rising tide. Or it might flow in slowly during spring tides and not at all during neaps. Anadromous fish returning to their natal rivers depend upon the outpouring water of the ebbing tide to bring them the scent of their destination, but they still may only enter the river as the tide floods, especially if the mouth is shallow. This is typical of salmon and sea-run trout.

Open Beach and Flats
Generally, tidal currents are weaker along an open stretch of beach or shoreline