This is post #2 in a series looking at small boat safety offshore. In this segment, we talk about some of the issues surrounding keeping your skiff afloat in treacherous times. Our previous post covered: “Getting Out and Back“.
Unsinkable Hulls vs. Self-bailing Hull Designs
In the US, hulls 20 feet and less in LOA must be unsinkable and have level floatation if swamped. That fact might give you a reasonable sense of security, but that’s not the ideal design from a offshore safety perspective. The preferred situation is to have a self-bailing hull design.
By “self-bailing” we’re talking about a hull that, if swamped, will empty out most of the water by itself. Hulls of this type typically have a low transom (or large scuppers with check valves) and a foam-filled hull, with little void space in the hull.
The idea is that if the hull is swamped, the foam prevents the hull from retaining too much water, and buoyancy is maintained. As the hull floats back to the surface, the low transom and scuppers allow much of the water to flow rapidly out the back, especially if there is any forward motion of the hull. In many cases, the engine powerhead is kept above water, so the motor will probably keep running.
The hull is not completely dry at first, but at least is buoyant and you can maintain steerage. As the boat moves forward, more water drains out the back scuppers, and is prevented from re-entering by the scupper check valves, so eventually the hull is drained.
The low transom does occasionally allow some water in over the transom under normal use, but it flows out just as easily. Our Edgewater 175 CC is built this way, as is the Whaler Montauk and several other extremely seaworthy hulls.
A number of companies sell conical wooden plugs that can be crammed into holes in your hull to plug them up. There are also a number of other devices on the market for temporarily plugging larger holes, but seem to be more oriented towards sailboats. If you think about it, with a foam-filled hull, the most likely problem will be a torn off through-hull fitting or a loose hose, both of which can be closed off temporarily with one of these babies.
Bilge Pumps (Auto/Manual, Hand Pump, Hi-water Alarms)
Think very carefully about your bilge pump capacity. David Pascoe’s website “Dockside Reports” has an excellent discussion on the issues of why small boats sink, and bilge pump capacity. The bottom line? You probably need a MUCH bigger pump that you have in your boat now .
Many boats come with automatic bilge pumps, i.e. the pump turns on when the water level reaches a certain point, then does not turn off until it drops past a certain point. This is a good idea, but keep in mind that you really need to know when the automatic pump comes on.
Assuming you do not regularily take on a lot of water, bilge pump activation is a very bad sign, and needs to be dealt with immediately (duh!). It is unlikely that you will be able to hear the bilge pump activate over the noise of your motor. Thus, some sort of hi-water alarm in the bilge is a good thing.
You should also carry some sort of secondary bailing device. This can be something as simple as a bucket, or as fancy as a mounted hand pump. We’ve opted for a portable hand pump from West Marine.
Just be sure that the exhaust hose is long enough to meet your needs. In a skiff, you would probably want a hose long enough to exhaust water over the side, rather than having to transfer it to a bucket for disposal.
If your boat loses power in heavy seas, it is critical to keep the bow of the boat headed into the wind and swell. Getting crosswise in a trough raises the real possibility of broaching, and turning stern-to in a large swell can be disastrous. Under these circumstances, having a sea anchor or large drift sock can be a life-saver.
Tossed overboard with a chain and long rode, and tied off on the bow, the extra drag will slow the drift, and keep the boat on the right heading, even with no power. It is something that is a good idea to carry, as it takes up little room.