To sink or not to sink: Expect the unexpected - Soundings Online

To sink or not to sink: Expect the unexpected

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Has your boat sunk yet? Fortunately, none of mine have. I did have one boat that was sunk when I got it and which, despite my best efforts, never floated. It was an old rotten three-log fishing boat that washed up in a storm and, after my best efforts, washed away in another storm. So that doesn’t count.

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I had a boat that I sank deliberately every spring and a few more times during the summer. I sank it in the spring because it was wood, and the bottom planks had to swell to close the seams. I sank it during the summer because I left chicken necks and meat in the bilge to “ripen” before I put them in my crab pots as bait. When my grass-cutting business got too demanding, sometimes I’d forget about the meat and by the time I remembered, the boat stank so badly I’d have to sink it for a few days to try to freshen it up.

That’s about the extent of my boat sinkings. However, I’ve had a lifetime of continuous effort at keeping my boats afloat and seeing other boats during and after their sinkings. I’ve learned that the causes of some sinkings are a bit unusual and sometimes catch people by surprise — as when they come down to the dock and see an oil slick where they had left their boat and a shimmering reflection of said boat below the surface. Here are a few of the sneaky ways boats sink.

Plants: Who would suspect the beautiful leaf as a sabotager of boats? Or the rose? Or pine needles? Or many other plants? It happens all the time, especially with center console boats. The leaves blow in on the breeze, and the rain washes them down to the scuppers in the stern. Soon they pile around the scupper holes and stop them up. It doesn’t take many leaves to do this, and often the very wind that brings the leaves also brings the rain. So the stern settles and settles until outside water begins to find its way in. If there’s a chop coming in from astern, the tops of the waves may find their way over the cutout for the outboard. And if someone doesn’t catch it, the rest is history unless you have a very powerful bilge pump that won’t ever discharge your battery.

Sometimes the best way to avoid catastrophe is to call in the cavalry.

Endangered species: Even if you’re in an area where no plant parts are likely to blow into your boat, consider the “endangered species” type of sinking. No, it’s never those of us with the sinking boats who are considered to be endangered by our all-wise government. A typical threatened species culprit in boat sinkings is the noble osprey. If one of them even starts to build a nest on our T-top or anywhere else aboard, we’re not supposed to “bother” them until they’ve had their babies, raised them to the point of launching and decided to move on.

There are various problems with this and I won’t mention them all, but one is that ospreys bring junk aboard like you wouldn’t believe. It’s not just leaves — it’s sticks, twigs, limbs, fish guts and droppings galore. Ospreys can clog scuppers better than a herd of beavers. Of course, when the boat sinks and all that oil and gas seep out, the EPA doesn’t like that, either. That’s when you and I become the endangered ones.

’Tween decks: This brings us to another sinking scenario, again often typical in center consoles. Most of these boats have a “ ’tween deck” area between the actual hull and the deck you walk on. Here resides the bilge pump — that savior of sinking boats. And usually in the aft deck area there are one or more hatches to allow access to the pump and whatever else may be living down in the ’tween deck space.

These hatches are often screwed down or closed with other types of fasteners, which rely in part on rubber gaskets or O-rings for sealing. These must be inspected and changed regularly because when that gasket or O-ring rots or disintegrates and the water creeps over the hatches, it can get below. And eventually the abuse of UV rays and the constant pressure of steps on those hatches can make them brittle, so they may leak even faster if one has been cracked. Of course, the bilge pump is supposed to take care of it, but a battery takes care of the bilge pump. How’s your battery?

Bilge pumps: Even if your battery is good, it may not be now because pumps and their switches aren’t immortal, and failures can be either in the “no run” mode or the less expected “always on” mode. The first mode can sink the boat in a direct way; the second is more subtle — it kills your battery. This can happen when a piece of debris finds its way under the float switch and holds the lever up so that the pump keeps running. Switch guards usually solve this problem. But there have been, and perhaps still are, pumps out there with self-contained switches that turn themselves on and keep running even though there’s no water in the boat.

Over the years, I’ve had several fail in the “run” mode. The last one, a Rule, was mounted above the water level in the bilge as an emergency backup. It began turning itself on, even though there was no water at the pump or its switch, depleting the batteries that fed it and the primary pumps. I spoke to the manufacturer and was told that the pump has been modified to avoid this. I’ve seen the new pump (model RM2000A), and the literature says the pump has circuitry that senses whether the pump is running dry — as can happen if debris has clogged the strainers — and that it will turn the pump off to avoid depleting batteries. The literature says it then checks for water every 2.5 minutes and runs again normally if water is present at the appropriate level.

This boat was safe and sound on its lift until a tropical storm filled the cockpit with rainwater.

The bottom line to avoid the real bottom line is to always check your bilge pumps. They’re often far out of sight but should never be out of mind. And don’t forget the wiring. It should be to manufacturer’s specifications and ABYC standards.

Lifts: Some seek to avoid sinking worries by leaving their boat up on a lift. Guess again. Insurance-claim records are full of incidents in which a scupper clogged with leaves or other debris while a boat was on a lift. The boat filled with rainwater, and the extra weight of all that water collapsed the lift, dumping the boat. Boat dumps are seldom graceful. Usually the aft lift fails first because the boat is wider, and thus heavier, back there, and the boat slides in and under stern-first. This is not a pretty sight.

Plugs: There have also been numerous cases in which owners have forgotten to pull the ’tween deck plug when they pulled the boat, either up on a lift or out of the water on a trailer. “No big deal,” you might say. But if the scuppers clog and the boat is no longer self- bailing, water can rise with the rains, and once the bilge pump quits, the boat gets very full.

And bilge pumps can quit even though they’re working well. Causes include battery discharge, water shorting wires, debris floating over a switch and good ol’ tropical storms, which eventually overwhelm small pumps. Even if the boat is on a trailer on dry land and can’t sink, the result can be almost as bad. When there’s enough water aboard to cover components, it’s essentially sunk.

The reverse situation also happens: We launch the boat, having forgotten to put that plug back in. Water pours into the ’tween deck space. Normally we see the bilge pump coming on, pushing water out the side. But you’d be amazed at the number of times the skipper hasn’t noticed the pump come on, hasn’t realized what it meant — “uh, maybe clearing a little bit of rain water” — or perhaps left the boat up against a dock so he can’t see the stream of water, which trickles off as the pump loses battery power and the water rapidly rises inside. The deeper a boat settles, the faster the water comes in through that breach.

Low sterns: I’ve noticed in recent years — even without “protected species,” leaves and owners leaving plugs out or in — that some center consoles get into trouble from water coming in astern. Walk down the dock and notice how many boats have huge outboards that weigh the stern down. You can tell something is wrong, in my opinion, when the highest tilt angle of the engine still doesn’t get all of the lower unit out of the water. This can be very bad for the outboard and indicates, in my view, either a lack of prudence in boat design or engine application.

The bottom line is that the stern is low and it’s heavily weighted. Then comes some weather. It happens even at the nicest marinas. Wind makes waves. If they are coming at the boat from the stern, they may come over that cutout for the outboard. As the wind rises, so does the influx of water. If current is running toward the stern, it’ll also be piling up water against the flat stern, making matters worse.

Theoretically that center console is self-bailing, meaning that the water will run right back out the aft scuppers. But if water piles in fast enough in a bad storm or with the help of a lot of rain, it can rise so far forward that it can start flooding below in the ’tween deck area through spaces around the console or other openings. And if those hatches we discussed earlier have bad gaskets or dry O-rings, it won’t even need to do that. It doesn’t take long for a wonderful center console to be pushed under in circumstances such as this.

Exhaust outlets: While on the subject of stern attack, I should mention that big exhaust hole back there if you have an inboard. It’s large enough to allow a huge amount of water to enter fast in the wrong circumstances. Most sailboats are built with a substantial rise or loop in the exhaust hose to prevent outside water from traveling through it during heeling. But many powerboats have little or no rise. This makes sense because the more you bend an exhaust hose, the more back pressure you put on the engine, which isn’t great for performance.

Also, in many powerboats the engines are above the waterline. However, if a storm blows heavy waves toward the stern while you think you’re safely docked, and if this oncoming water is augmented by a strong current running to the stern, that water buildup can be pushed into the exhaust and ultimately into the engine. There would have to be quite a bit of water over a long time for this to actually sink the boat, but if your engine fills with salt water, you may wish it had sunk. And it isn’t unusual for the hose clamps fastening the exhaust hose to the exhaust port to loosen, because that hose is constantly moving a little as the exhaust bellows out.

Stuffing box: Speaking of exhaust, some use exhaust hose to connect the shaft log to the stuffing box. This can lead to flooding with so little warning that you may not have time to do anything about it but call for help and start swimming. Exhaust hose typically isn’t thick enough to resist twisting or turning when you apply the torque that a hose in this application must endure when changing the packing gland nut and then retightening it.

However, these hoses also can suffer extreme torque just from daily running. As the shaft turns, it is stressing the hose to some degree, depending on various things, including the tightness of the stuffing gland (shouldn’t be too tight), the size of the shaft and lubrication. Sometimes the running torque will tear these thinner hoses, particularly if they have some age, and water floods the boat at a very high rate. Remember, the farther under water the breach, the greater the water pressure and, thus, the inflow.

Also, wire inserts, often in exhaust hoses, though OK for some applications, may rust and break when used with a stuffing box/shaft log connection hose because of the constant vibration and torque as you run. Over time, this can cause cracking in the hose lining, introducing salt water to the wire insert, which can increase rusting. Eventually the wire will begin to cut into the hose liner, allowing leakage and an increased likelihood of twisting and cataclysmic tearing.

There is hose made specifically for this type of application, generally referred to as “packing box” or “stuffing box” hose. This typically has a thickness of 5 ply and is custom-made for the purpose, according to Steve Gaston of Hydrasearch (Buck Algonquin Marine Hardware). The plies are composed of alternating layers of synthetic material vulcanized together before completion.

Still in this department, that shaft hose can really do a number on hose clamps. You know what can happen when a hose clamp comes loose or disintegrates. Be sure to use four high-quality hose clamps — two at each end. They should be 316 stainless completely, including the band and the barrel and gear. Clamps with weld spots rather than mechanical construction may be weaker because of the frailties of welding materials in conjunction with the base material and salt water.

The edges should be rounded to avoid cutting into the hose, and the perforations should not be all the way through the band. This is particularly important because these hose clamps are typically sprayed with salt water and there is a high likelihood of failure with inadequate clamps. It’s important to check the clamps and hose regularly. New clamps often need tightening after a few hours of running. Remember, the hose is constantly moving a bit as you run.

High-pressure hoses: Other engine hoses can also sink a boat or cause enough flooding for serious damage. We all hear that hoses below the waterline should have double clamps. However, it isn’t unusual to see water-passage hoses on engines with just one clamp. Why not, one thinks, if the engine is not below the waterline?

First, remember that the waterline can be a relative thing at sea, as when a boat is heeled from wind or waves — and this does not only happen to sailboats. Second, even if the engine is well above the waterline, there’s a raw-water impeller pump pushing outside water through those lines at considerable volume and pressure. If that hose backs off a fitting, water may come shooting into the engine room, damaging vital components. This can include wiring, causing shorts that can cause fire or a battery short that can kill a bilge pump. The forced flooding will stop soon because the engine will overheat and die, but the damage can be considerable, perhaps enough to contribute to a sinking.

High-capacity pumps, and professional help, kept this boat from finding the bottom.

The idea that hoses only need to be double-clamped below the waterline is a problem in other areas. Some sinkings have occurred where a hose well above the waterline — for example, attached to a cockpit drain — came off at the drain. The owner wouldn’t normally see this because it’s under a deck or cockpit. But rain or other water coming in is going to go straight into the bilge rather than out the side, as it’s supposed to.

The tub effect: Admittedly, some of the scenarios painted here haven’t involved enough water coming into a boat to sink it. But think again. Water in a boat, particularly a boat with open spaces, such as a center console, can quickly reduce stability to such an extent that the boat capsizes or dips a gunwale under the surface, resulting in sudden massive flooding. This can occur so quickly that those aboard don’t realize what’s happening until it’s too late.

Depending on the size and type of boat, different things contribute to this sudden destabilization. Waves rocking the boat, movement of the passengers — as perhaps moving to get a bailing bucket — a turn while underway or a wake can cause a sudden shift in the very heavy load of water. It sloshes back and forth in heavy waves, either from side to side or, if the balance is precarious enough, maybe to just one side that goes under.

A gallon of water weighs about 8 pounds. You can’t know how much water you’ll have in your boat, but you can see that a considerable amount, once it starts moving, can easily destroy your boat’s stability. And once the water starts moving, it may be too late to stabilize the boat before the capsize or sudden sinking.

You might think enough water coming aboard quickly enough to destabilize a boat would be rare. Unfortunately, this is not necessarily so. An inboard engine hose spurting out forced volumes of water can add enough. A busted stuffing box hose could easily do this. Water coming over the side or over the bow in rough seas can do the same, particularly if it doesn’t drain or isn’t pumped out fast enough.

And then there’s the phenomenon of pushing the flat end of the boat into the waves instead of the pointy end. It happens all the time, especially when fishing. Backing down into the sea can cause huge amounts of water to suddenly come over the transom. Fortunately, most fishing boats are built with large-volume self-bailing capacity and can handle this. Also, this is usually a deliberate maneuver, with the helmsperson looking aft and aware of what’s going on. However, sea motion or occupant motion in the boat while that water’s still aboard can cause catastrophic results if it’s not anticipated and handled properly.

Lightning: We all know lightning is extremely dangerous and that a strike on a boat can ruin the electronics, all of the wiring, start fires — the horrors go on. But there’s one result of a lightning strike that is often unanticipated, and it occurs on fiberglass boats.

When lightning hits a boat, it seeks to “escape” to ground. It wants the quickest, straightest way out with the least impedance. Many try to provide as direct a route out as is possible. Sometimes this is heavy cable running straight down from the highest mast to a ground plate outside the hull. Some run lightning “exit” cables from stays or throw the ends of cables over in a storm, with the top end attached to a T-top. How well these measures work is often debated, as is the best material and the best way to install it. I only know for sure that it makes me feel better to provide an exit pathway.

But I’ve seen lightning strikes seriously harm boats and equipment, even with carefully installed, state-of-the-art lightning equipment. The bottom line is that you never know the amount of voltage and other factors. The other bottom line is what it does to your bottom line.

If lightning doesn’t get out fast and easy enough, it can go right through the bottom of a boat. This can be very obvious, as when it blows out a through-hull fitting. Suddenly there’s a big hole with lots of water flooding in. But it can also cause thousands of tiny pinholes in a fiberglass hull as the voltage passes through. These may be hardly noticeable at first. And as you race around the boat — checking to see what has survived, whether there’s fire, whether anyone’s hurt — you may not think about the fact that your hull is no longer watertight and the sea is beginning to seep in. Sometimes when this occurs, the boat fills and settles rather fast. But if your electrical system, and therefore your bilge pump, is gone, all the buckets in the world may not be enough once you do realize what’s happening.

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So I’ve painted a lot of doomsday scenarios here, but most can be handled successfully if you know what to expect. Just keep in mind these and other possibilities, and you’ll probably have a lifetime of safe, fun boating — above the water, where we all prefer to be.

October 2014 issue