It is one of the few indisputable truths to come down through the ages: The fundamental purpose of a boat is to keep water where it belongs — outside of the boat. It doesn’t always happen, though. Mother Nature and Mr. Murphy can combine forces and allow the ingress of water.
Before continuing, I must give credit to Ray Dennison, commander of Coast Guard Auxiliary Flotilla 2408 in Clinton, Conn. In June the flotilla brought a Coast Guard Damage Control Demonstration Trailer from Sector Long Island Sound to the West Marine retail store in Clinton. They showed live examples (read: wet) of things that can go wrong on board, and demonstrated fixes. Keep in mind that these are temporary fixes to keep your boat afloat, and will need proper attention back at the dock.
1. One of the scenarios demonstrated was a ruptured water intake hose. Even under considerable pressure, they made a temporary repair using duct tape. The secret is to begin wrapping the tape around a still-dry portion of hose using a generous overlap, since the tape won’t stick to a wet surface. Working from a secure base around the dry hose, force the tape over the rupture and continue on to a dry portion of the hose beyond the damaged area. After establishing a good base, wrap the tape back to its starting point. If necessary, repeat the procedure.
2. If you don’t have the luxury of dry hose on both sides of the rupture, wrap plastic from a garbage bag or similar material around the hose and lash it tightly over the damaged section with 1/8- or 3/16-inch-diameter line. Close the rupture by squeezing it using a so-called “Spanish windlass.” It’s a simple rig using a screwdriver for leverage; look for it in a good book on knots or marlinspike seamanship. Be careful not to crush the hose; you’ll still need it to bring raw water to the engine. After you’ve finished the repair, dry the area and tape it with duct tape.
3. Another problem illustrated was failure of a seacock or through-hull fitting. The volume of water gushing through even a 3/4-inch aperture per minute a foot under water is frightening. Each seacock and through-hull fitting should have a tapered plug made of soft wood secured to it by a length of line. Simply jam the plug into the hole if there is a failure. It’s a good idea to have a rubber mallet handy to drive it home. Most boating supply stores sell packages of these plugs, or bungs, in assorted sizes, though size isn’t really an issue since the plugs are tapered.
4. Sometimes it’s the manifold or muffler that violates the prime directive of keeping water on the outside of the boat. And their shape might be such that duct tape cannot be used. However, using light line — 1/8- to 1/4-inch in diameter and preferably of natural fiber that will absorb water and swell — you can affect a similar repair. Common sisal is a good choice; it’s inexpensive and available as packaging cord. Start with a clove hitch and tightly wrap the line around the damaged area until you’ve covered the break. Continue wrapping well past the damage, form another half-hitch, and go back the other way with riding turns. Don’t make the riding turns so tight as to work them into the original turns; you don’t want to open gaps. Think of this repair as if you were seizing something — wire, rope or shafts of wood. Keep in mind that this repair might not completely stop the leak. As the rope swells it should reduce the ingress to where the bilge pumps can handle the volume, assuming you have adequate bilge pumps.
5. If Murphy is working overtime, the break will have occurred in a weld at a “T” or an elbow. The technique is essentially the same but you’ll be wrapping the line to form something akin to a square lashing, where two struts are lashed at right angles.
6. If Murphy is working double-time, the break will have occurred at a weld on the outside of an elbow. This can be very difficult to repair because water likely has sprayed a large area, so duct tape won’t hold. If the pressure isn’t too great you should be able to patch with epoxy putty or a similar product that will cure and adhere to wet surfaces.
7. To slow the ingress of water though a breach in the hull, you can try an old seafaring technique called “fothering.” Pass and secure a tarp or large piece of vinyl or plastic, such as shrink wrap, from port to starboard beneath the boat. Depending on the location of the breach, someone may have to get in the water to help it along. The force of the water against the hull pushes the tarp or vinyl against the breach and should slow the leak enough to buy some time until help arrives. You might even be able to very slowly motor to shore. As an added measure, you also can patch the hull from the inside with a suitable epoxy, or jam a flotation seat against the breach.