The greatest single emergency any boat can face is loss of hull and integrity, better know as a hole! This can come from collisions, striking containers discarded by ships at sea, which is one of the most murderous acts that takes place on the water nowadays, or from large sea life.
Consider the danger from a hole big enough to threaten sinking your boat. A hole threatens life. A leak allows you time to deal with it. Even a small hole will let in 80 gallons of water per minute. A fist-sized hole well below the waterline will let in water under pressure at a rate that most ship’s bilge pumps will not be able to handle. A boat engine driven pump handles between 100 to 450 gallons a minute, so that is the only way to stem the flow from a reasonably small hole. In some cases damage to the hull will be so great that the only option left to a crew is to take the life raft and as much emergency equipment as possible.
For the moment we’ll assume we have some chance of beating the water. First cut down the inflow by placing a cabin cushion or pillow over it, then wedge a piece of timber against the cushion, even if the timber has to go right across the hull. That should bring the flow down to the level of a leak and provide time to deal with the problem permanently. If the hole is not easy to reach, you may have to remove some the boat’s fittings to get at it. If the hole is deep in the hull, you probably need to start fothering it immediately, but if not, there are a few steps you can take before fothering.
The first is to calculate whether the boat can heel enough to bring the hole above water level, or to make it intermittently above water level. This has two benefits. First, much less water will get in, and, second, the hole will be in an area where it can be worked on directly from outside as well as inside. Heeling to get a hole higher is useful even if the hole is relatively deep. Going on the tack that raises the hole, even if it doesn’t raise it above sea level, will reduce pressure causing the rate of water entering the boat to be less. Force an abnormal amount of heel on the vessel by moving the anchors to one side and shifting all the sails and other heavy equipment that can be moved, as long as this doesn’t affect stability.
With timber vessels, the method of repair, if the hole can be reached, is to tack some pliable, thinnish plywood over the hole, with a sealant between the plywood and the outside of the hull. The flow of water will almost stop. Then, inside the hull the hole can be filled with epoxy and a tingle nailed to the hull from the inside. This tingle can be either another piece of ply, a cut-open tin or piece of flat metal, or anything that can be held firm and that will hold the sealing compound in place while it sets.
If the hole is further down the hull, depending on conditions, quick sealing epoxy can be put into the hole in the same way, but it’s more likely that the conditions will be difficult and the problems of the vessel might be compounded if someone were put over the side to handle the repair.
These are just a few ideas you can use to quickly recover from the unforeseen disaster of a hole in your boat.