THE SHARPIE LAUNCH

     In the United States there are a number of flat-bottom launches used in shoal and relatively protected waters, such as rivers, lakes and bays. The Sharpie is one, and is used on Long Island Sound and the rivers emptying into it, the Mississippi river, and on the Chesapeake, particularly in the crab fisheries. There is much variety of the model but, in the main, construction is standard. Fig. 4 represents a small Chesapeake Sharpie launch not much different from that used on Long Island Sound. It is like a flat-bottom rowing skiff except that the transom is slightly immersed and the fore-and-aft rocker of the bottom is slight. The beam is usually small on the bottom, the flare giving the appearance of greater width than is actually the case.

     It is one of the least expensive launches and is suitable for fishing shallow, semi-protected waters. Experience has shown that a wide beam is undesirable if speed is wanted and, as the speed is increased, the amount of rocker must be decreased to obtain the best results. It also appears important to make the chine profile straight, toward the ends of the hull, as in the example shown here. The models in use are up to about 50 ft. (15.3 m.) in length. They venture to sea in good weather but they are not good boats in open water as they pound heavily in a rough sea. But in sheltered waters they are superior boats and most economical to build.

     Sharpies are usually powered with one- or two-cylinder marine engines, 3 to 9 h.p., which give them speeds ranging from 5 to 7 knots. With an automobile engine, large skiffs will run at speeds in excess of 17 knots in smooth water.

     The usual construction is that employed in a rowing skiff. The sides are bent around moulds placed bottom up. A bent plank-keelson is laid down and the bottom plank is laid on athwartship. The stems are usually in two parts, an inner piece, or liner, to which the sides are nailed and a cutwater added afterwards, to cover the ends of the side planks. The side frames are no more than cleats set on edge, wide at the head to support the side deck, no deckbeams being required along the run of the- cockpit coaming. Stiffness in the open hull is obtained by the use of bulkheads, one at bow and one at the stern, with a deep floor formed of a wide plank on edge amidships or, as an alternative, one or more thwarts. Large boats have a cross floor at each end of the engine bearers, with the ends kneed to the sides.

     As building costs must be kept down it is common to have the propeller shaft alongside the skeg rather than passed through it. The side position not only avoids the labour of boring the shaft hole but also simplifies the aligning of the shaft and its installation. The stern bearing is through-bolted to the side of the skeg and usually has a rubber bushing, water-lubricated. The stuffing box is inside the hull, mounted on a block. This places the shaft and engine slightly off the centre line of the hull and it is usual to put the shaft on the side opposite to which the propeller turns. The effect of the off-centre position of the engine on transverse trim cannot be observed, the weight of the battery probably being used to counteract such influence in the narrow skiffs.