A very common place for leaks to develop is in the rabbet between the garboard and keel, just under the mast. This is due to the downward thrust and working of the spar. If a boat persists in leaking there, lengthen the mast step so as to distribute the strain over a larger space. Our modern plank-keel boats are liable to develop cracks in the plank, which will only leak when underway, and are difficult to discover, as they close up when the boat is at rest. If the leak is bad it can be readily found by hauling the boat out, filling her bilge with water and watching where it drips out.
Leaks, stopping:
You can sometimes stop or check a leak by calking from the inside, if you can get at it; but great care should be exercised in driving the cotton not to push it in too hard, as you may drive out what calking is in the seam, and make the leak worse. Holes, if they can be got at from the outside, can be covered with sheet lead, copper, or a piece of rubber boot leg. In an emergency the same can be used inside to check the flow. Barge men frequently use horse manure to stop leaks in the seams when near the water line; they throw it overboard and let the water draw it into the crevice. I have checked a leak by running a boat on a bar of soft sand, thus getting sand in the seam.
Leak, to frap a:
If you get a hole in the bottom from striking a rock or other obstruction, and cannot put the boat ashore on a safe place, you can check it enough to keep her afloat by what is called frapping. Take a sail or large piece of canvas, and fasten a line to each of the four corners, then on the inside of the canvas sew a lot of oakum or cotton so as to make a wad big enough to completely cover the hole and a large space around it. Pass two of the lines under the boat and bring them up on the side opposite to the one the leak is on; keep the other two on the side the leak is. Work the canvas along until it covers the hole, and then haul all the lines taut, and make fast, the pressure will force the wadding into the hole and check the inflow of water until you can lay the boat ashore.
Scupper-pipe leaking:
If you get a bad leak in the scupper pipe, and cannot get at it from the inside, the following method is a quick and sure way of stopping the inflow of water: Cut a round disk of wood about five times bigger across than the outside opening of the pipe. Bore a hole in the middle of this disk just small enough to pass a strong cord through and knot. Then on inside of the disk fasten a good big wad of cotton batting, or oakum; this you can do with tacks, thread or glue. I have used thick paint and cotton wadding pulled out of an old quilt. When the disk is ready, take another line and weight it with a sinker, drop it down the scupper pipe until it hangs outside, then fish it up with a boat hook and bring the end on board. Marry the end of this cord to the cord attached to the disk. Then haul the cord in through the pipe until the disk comes up against and closes the scupper hole. By taking a stick and making a windlass of it you can roll the cord up tightly and secure the disk so it will not slip.
Lookout reports:
The lookout should examine the side lights, at least every half hour, and report to the man aft in command their condition. He should also see that the set of the headsails do not cover the lee light. If so, be prepared to show it clear if a vessel approaches on that bow.