Understanding the influence of tides is vital to fishing success. Tide is generally referred to as the vertical rise and fall of water due to the gravity of the moon and sun. Under a full or new moon, the gravity from the moon and sun are additive. During these times, the greatest tidal changes occur. The tides of the full or new moon are called spring tides.
Tides in the Chesapeake Bay are semi-diurnal, meaning there are two highs and to lows per day. It takes a little over six hours for the tide to change from one extreme to the other. While vertical tidal changes on the Chesapeake are small (~2ft.), they impact the location of fish in shallow water. As a general rule, gamefish like striped bass move closer to shore on high tides to feed around structure that they cannot safely reach on low tides.
When fishing the shallows, it is important to notice the tidal height when you find fish at specific locations. During extreme highs or lows, you will find fish in areas that typically do not hold them. Generally extreme tides are the combination of the general gravitational forces plus the influence of wind.
Strong wind can push large amounts of water causing a raise or fall in water level. Here on the western shore of the Chesapeake, strong northeast wind will stack up the water causing abnormally high tides, while strong southwest wind will cause abnormally low tides. I also find that during fall and winter, the tides tend to run lower on average – possibly due to the tilt of the earth’s axis.
Horizontal current is created from vertical tidal movement. Fish are opportunist feeders and rely on current to catch smaller prey in the fast moving water. As a general rule, fish feed most actively during times of strong current. For example, it is critical to fish a fast moving current at night when targeting stripers under the bridge lights of the Chesapeake Bay Bridge Tunnel.
Current direction will influence where fish will congregate. I will only fish certain spots on an outgoing current and others on an incoming current based on the way water moves around particular points, channels or structure. Understanding local variations in current flow for your given area is important.
I find that the time of slack current can vary greatly in a short distance. There are spots that I fish 1 mile offshore where the time of slack current occurs 1.5 hours later than directly inshore. Using this knowledge can help you plan your day to take advantage of moving current.
Wind can play a role in current, as well. If a strong wind is blowing in the same direction as the tidal driven current, the current speed will increase and vice versa. On the Chesapeake’s western shore, it is a good idea to plan to fish an incoming current during a strong NE wind, because the wind and tide will be working together causing faster moving current. During a strong SW wind, you will want to do the exact opposite and fish the outgoing current.
I hope you have found this tutorial to be useful, because understanding tides and current can help decode the mystery of fishing!