Article by Capt. Mark Sampson
Last week I wrote about what boaters should to do if they run aground and included a few tips on getting unstuck. But after reflecting upon what I wrote, I realized that perhaps it would have been better if I started out with more helpful suggestions about how boaters can keep their boat off the bottom in the first place.
I did mention that it’s always good to start with studying a local chart and have it available for quick reference, watch where other boats travel and go slow when not familiar with the waters, because those few guidelines alone should keep boaters who venture away from marked channels off the bottom most of the time. But no matter how much you plan ahead and try and do the right thing, if you’re zipping around the inshore waters, it’s easy to get a little off your planned course and suddenly find yourself worrying about whether or not you’re headed towards water that’s measured in “feet” or mere “inches.”
At times like that, it’s tough to know whether to slow down and hope you don’t bump bottom as you come off plane, maintain course and speed and hope for the best or throw her into a big u-turn and get your butt back to where you know the water is deep enough. Any of those could be the right call at the time, but it all depends upon how you “read the water.”
Being able to read the water refers to the ability to look at the surface and discern what is going on beneath it. The depth, the edges of channels and shoals, currents, tides, the presence of fish or other marine life, the location of rocks, reefs or wrecks, there’s so much that can be figured out if someone knows how to interpret the sometimes subtle, and sometimes obvious, features of the water. But for now, I’ll just stick to what might indicate a change of depth.
Ripples on the water: Even when there is absolutely “zero” wind, and most of the bay is glassy calm, there will usually be patches of rippled water which might result from a number of conditions such as a small and localized breath of wind or even a school of fish, but it can also be from where the current is flowing across some shallow water. But then again, the same can hold true for an unusually calm bit of water that might be from any number of things, including the presence of extra shallow depths, particularly if there is any kind of vegetation (seaweed) growing there.
Color change: There’s nothing like cruising the bay on a sunny, calm day when the water is clear and the sun is at your back. Under those conditions, the sandy shoals and deeper channels can contrast each other like the strips on a zebra. Unfortunately, the water’s not always that clear, and if you have a surface chop or cloud cover, it be all the more difficult to see bottom. But even under less than ideal conditions, with the aid of a good pair of polarized sunglasses, different shades of color can often be picked out enough to tell a boater that there is some kind of a depth change coming up that they might need to avoid.
Different size waves: As wind driven waves move across a body of water, they usually stay the same height and distance apart as long as everything else stays constant. But just like we see on the beach, when waves move into shallow water, they get steeper, closer together and will often break. Such differences in wave characteristics are a good indicator of shallow water.
Weed or trash lines: Offshore anglers are familiar with weed lines or even trash lines where wind and/or currents push together long lines of floating debris. The same can sometimes happen in inshore waters when a breeze pushes debris up against a current that’s ripping around a shoal. Anytime boaters notice even small amounts of trash or grass drifting in a line, they should be suspicious of a change of depth on either side.
Upwellings: When moving water is pushed against an underwater obstruction, such as a shoal, a wreck or a rock, it will move over and around whatever is in it’s path. If the current is strong enough and the water shallow enough, water that is pushed over the obstruction will often go straight up to the surface in a plume, known as an “upwelling.” Though upwellings will not always indicate a hazard to navigation, they do always indicate that there is some kind of change in depth or bottom structure and boaters should be very careful about crossing over them.
Crab traps: Commercial wire crab traps or “pots” stand about 20-inches high and have floats that mark their location. The traps are usually set out from a boat as it moves along in one direction. Seeing a string of pots doesn’t necessarily mean that the water there is particularly deep, but the boats that put them out are usually fairly good size and as long as the traps themselves aren’t visible above the water, those in small boats can at least be reassured that the water is at least 20-inches deep or more around the floats.
Sea birds: Birds can give hints to water depth, but their actions require a lot of interpretation. Birds will often dive on bait at the edge of the bar, but diving birds don’t always mean deep water is near because some birds, like little terns, will often dive on bait, even in very shallow water. Birds tend to float in water that at least have a little bit of depth to it, but before someone runs close to any floating birds, they had better make sure they’re swimming and not standing!
The ability to read the water is not something that can be learned from a book or a 15-minute instructional video. Those who are good at it will probably admit that their talent is the end result of experience, intuition and a lot of bent propellers!
Captain Mark Sampson is an outdoor writer and captain of the charter boat “Fish Finder”.
