In the Northeast, there is no other force that has such a pervasive impact on fish than the tide. To understand why fish are where they are, and why they do what
they do, you should try to learn as much as possible about the tides in your area.
First off, tides are caused by the gravitational pull of both the Moon and the Sun. They are also subject to environmental variances, such as wind, etc., which is why
they call tide charts "predictions," not "schedules." Due to the complex interaction of the pulls of both Sun and Moon, the heights of the tides also vary. For example,
over the next four months, the highest tide in Boston Harbor will be 11.80 feet on September 8 at 18 minutes after midnight. Similarly, the lowest tide will be -1.46
feet on September 9 at 7:23 a.m. That's a total tidal swing of 13.26 feet, which makes a tremendous difference in the conditions you will find on the water.
There is approximately a 6-hour difference between high and low tide and daily the tides progress about an hour ahead. If it is high tide today at noon, tomorrow it will be about 12:50. Due to this daily change, you can expect that if the tide was high at noontime last Saturday, next Saturday, it will be low. Also, if you encountered favorable conditions at your favorite spot at sunrise today, in two weeks, you could
reasonably expect the same sort of conditions to exist.
So why does this tidal movement of water have such an impact on the fishing? It does several things. Firstly, higher tides open new areas to the fish to feed. Flats
that are fully exposed at lower tides become covered with enough water that stripers are able to disperse across them foraging for mussel beds, crabs, baitfish, etc. For a specific example, I would point to Button Island in Hingham, which you can walk to for more than half the tide. Yet it has produced fish over 40 pounds in the past couple years (not regularly, so don't be in a hurry to plan a trip targeting that island specifically).
Phil Collins, the Mad Kiwi (okay, they may be all mad, but that is another topic) points out that one of his favorite techniques in New Zealand is to look around during a daylight low tide for the holes grouper have dug in the bottom. Then he returns at night, and casts to the same spots. This trick has netted him some very large grouper over the years.
Additionally, the flow of tidal water creates strong current flows, which in turn creates rips. Bass love rips. I won't say that big bass are lazy, but they are certainly efficient (come to think of it, I too am becoming more efficient as I age). They will find a spot where they can sit in an eddy, perhaps behind a rock and wait for the bait to be swept down to them. Not only can they conserve energy, but they also place themselves in a position where they can capitalize on a concentration of bait. Simply put, they tend to get more feeding opportunities when they feed in rips.
At lower tidal stages, fish and bait tend to be more concentrated. You'll often find fish by working the channel edges where water and bait is draining back off the flats. This is a time when you may also find schools of larger bait like herring or bunker (menhaden, pogie, etc.) getting balled up and marauded by linesiders.
The character of the waters you fish changes subtly by the minute as the tide changes. Areas that may hold fish on the outgoing tide between +8 and +7 feet,
may be very unattractive to fish on the incoming tide at the same stage. Similarly, an area like Blacks Creek will fish well for a particular window of time during a
particular tide, such as 2-3 hours into the outgoing. You need to learn what stage of tide works at the spots where you fish, keeping in mind that simply noting the time of the tide may not give you a reproducible result, if you do not also pay attention to the height of that tide. To put it more clearly, an area may fish well at 2 hours past the high on an astronomically high tide, yet on a lower tide, it may fish well at 1 hour past the high.
Tides do not affect only fishing. As Capt. Bill Smith has pointed out in the past, astronomically high tides in Boston Harbor create navigational hazards as well. The action of an extra foot or so of water is sometimes all that is needed to pull free some of the millions of abandoned, rotting wood pilings that have accumulated in the harbor from nearly 400 years of use. These pilings have a nasty habit of floating just under the water, where you can't easily see them, yet your prop or lower unit is sure to find them. Astronomical lows are the perfect time to drive around on scouting trips. You will find hints of structure that you would never see otherwise. A smart angler will use these tides to mark areas to investigate later.
Seasoned mariners also realize that the combination of an onshore wind and an outgoing tide at the Merrimack River or North River can produce deadly
consequences. Large standing waves can build at the mouth, which makes it dangerous and all too often deadly. These are the times you should consider
diverting to another port or riding out the weather offshore until the turn of the tide. This point was unfortunately made the hard way this week as an angler lost his life at the mouth of the Merrimack.
Captain John Bunar of Skippy III Charters relates this information to the Plymouth
area:
Just to add some local color to what Mark had to say about tides. In the Duxbury/Plymouth area, there are many areas that only produce action
during small windows of the tide. A fishermen can catch fish pretty much every time out if he learns the general "laws" of the bays.
On dead lows and especially minus tides, it is best to work the weedy edges of Guzzles and secondary channels. These areas show well on a chart so
making a plan before you go fishing will keep you effort organized. When the water starts to come up of those edges with the incoming tide, The most consistent fishing I have found is up on the shallow, patchy grass flats often adjacent to the guzzle or channel edge I have been fishing. Some of the clear water sand flats towards Cordage Park offer up sight fishing so they can we worth a shot as well. Keeping your offering on or near the surface during this stage of the tide seems to produce best and keeps you from constantly removing salad from your lure or fly.
As the half tide passes, I think it is best to think about fishing some of the shoreline structures like the rocks at Gurnet Pt or some of the cuts in the
marsh behind Clarks Island. The marsh areas are especially interesting because they offer so many little nooks and crannies where a fish may be
holding. Other areas to try this type of fishing are the Jones River in Kingston and the Bluefish River in Duxbury. My opinion is that it is best to fish these types of areas through the high tide.
As the water starts to recede from the bay, some of the feeding spots are obvious. Early in the season, areas like the Saquish and Kingston rips are no brainers. As the season works it's way through June, a fisherman needs to locate and fish the more subtle flows and rips. My best advice here is to scan a chart for areas where you think the tidal flow will be compressed or accelerated by the geography of an area. An example of this would be the point of Plymouth Beach. There are many high sand bars that effect current in the bays - fish use almost all of these areas on the outgoing.