Glossary.qxd 8/25/04 11:35 AM Page G-1 AMPHIBIAN —A seaplane with retractable wheel-type landing gear that can be extended to allow landings to be made on land. BUOYS —Floating objects moored to the bottom to mark a channel, waterway or obstruction. CAN BUOYS — Cylindrical buoys marking the left side of a channel for an inbound vessel. They have odd numbers which increase from seaward. ANCHOR —A heavy hook con- nected to the seaplane by a line or cable, intended to dig into the bottom and keep the seaplane from drifting. CAPSIZE —T overturn. DAYBEACONS — Unlighted beacons. DAYMARKS —Conspicuous markings or shapes that aid in making navigational aids readily visible and easy to identify against daylight viewing back- grounds. CAST OFF —T o release or untie a vessel from its mooring point. AUXILIARY FIN  — An addi- tional vertical stabilizer installed on some float planes to offset the increased surface area of the floats in front of the center of gravity.  CENTEROF B UOYANCY —The average point of buoyancy in float- ing objects. W eight added above this point will cause the floating object to sit deeper in the water in a level attitude. BEACHING —Pulling a seaplane up onto a suitable shore so that its weight is supported by relatively dry ground rather than water. BEAUFORT WIND SCALE —A standardized scale ranging from 0-12 correlating the velocity of the wind with predictable surface features of the water. BILGE —The lowest point inside a float, hull, or watertight compartment. BILGE PUMP —A pump used to extract water that has leaked into the bilge of a float or flying boat. BULKHEAD —A structural parti- tion that divides a float or a flying boat hull into separate compartments and provides additional strength. BUOYANCY —The tendency of a body to float or to rise when submerged in a fluid. CURRENT  — The horizontal movement of a body of water. CREST —The top of a wave. COMBINA TION SKI — A type of aircraft ski that can be used on snow or ice, but that also allows the use of the skiplane’ wheels for landing on runways. CHOP — A roughened condition of the sea surface caused by local winds. It is characterized by its irregularity short distance between crests, and whitecaps. CHINE —The longitudinal seam joining the sides to the bottom of the float. The chines serve a structural purpose, transmitting loads from the bottoms to the sides of the floats. They also serve a hydrodynamic purpose, guiding water away from the float, reducing spray, and con- tributing to hydrodynamic lift. DECK —The top of the float, which can serve as a step or walk- way. Bilge pump openings, hand hole covers, and mooring cleats are typically located along the deck. DISPLACEMENT  POSITION —The attitude of the seaplane when its entire weight is supported by the buoyancy of the floats, as it is when at rest or dur- ing a slow taxi. Also called the idling position. DOCK —To secure a seaplane to a permanent structure fixed to the shore. As a noun, the platform or structure to which the seaplane is secured. DOWNSWELL —Motion in the same direction the swell is moving. FETCH —An area where wind is generating waves on the water sur- face. Also the distance the waves have been driven by the wind blowing in a constant direction without obstruction. FLOATPLANE  — A seaplane equipped with separate floats to support the fuselage well above the water surface. FLOATS —The components of a floatplane’s landing gear that provide the buoyancy to keep the airplane afloat. G-1