Afterplane:
1) the bottom surface aft of the break, normally flat and Parallel to
the water surface;
2) the entire main hull aft of the sponsons; the
"fuselage."
Air Dam:
an aerodynamic device or spoiler in the tunnel under the bow or leading
edge of a three-point hydroplane; typically a flat strip set on edge
laterally (crosswise), it creates turbulence thus reducing lift.
Air Trap:
1) the aftward continuation of the inside vertical "walls" of the sponsons,
forming tunnel sides and channeling high-pressure air forced underneath
by the boat's shape and forward motion;
2) the inside vertical "wall"
of sponson and air trap from bow to stern; the tunnel side.
Airfoil:
The cross-sectional profile of a wing.
Angle
of Attack:
1)
hydrodynamically, the designed angle between the planing surface of
the sponson and the surface of the water, measured fore and aft;
2)
aerodynamically, the angle between the chordline of a hydroplane's wing
and the apparent wind.
Angle
of Incidence:
the designed angle between the chordline of a hydroplane's wing and
the water surface; the angle is fixed for ram wings but adjustable for
auxiliary devices such as the horizontal stabilizer.
Break:
the transverse juncture where the forward, angled part of a hull bottom
meets the afterplane on a three-point hydroplane.
Bustle:
a fixed hydrodynamic shape on a chine, which enlarges the area available
for buoyancy, especially when the boat is turning.
Cabover:
Rear-engined boat, with driver
sitting ahead of engine.
Canard:
1) a small, forward-mounted wing, usually between the sponsons and often
adjustable for trim, either by pivoting about a lateral axis or by hinged
or sliding flaps on the trailing edge; also "foreplane" or "noseplane"
in aeronautical terms;
2) a reverse three-point (actually four-point)
hull configuration, a "tricycle," with two sponsons aft and a planing
shoe forward.
Canoe:
a construction element of modern three-point hydroplanes, including
sponson, chines, and air trap full length from bow to stern, molded
as one piece.
Chief Board:
Long board of white oak located on the left side to give added support where
the boat will rest on the trailer when on tilt.
Chine:
the inclined side of hull or sponson; also "non-trip."
Chordline:
the imaginary straight line from leading edge to trailing edge of an
airfoil, this distance being the "chord."
Compton Block:
Blocking inside of sponsons where the step occurs on the primary
running surface. Aptly named when Steve Compton could NOT get it right
after three attemps and out of frustration told Rob Wheeler that he'd
better make the D*#n thing!
Deck:
the top or upper surface of hull; decking.
Dihedral:
hydrodynamically, the designed angle between the planing surface of
the sponson and the surface of the water, measured laterally inside
to outside; a negative angle is called anhedral.
Elevators:
movable surfaces on the trailing edge of canards or ram wings that direct
airflow; also ailerons, flaps, flippers.
Engine
Hood:
a part of the cowling that covers the engine and engine compartment.
Engine:
by rule, an inboard, internal-combustion powerplant either reciprocating
or gas turbine.
Fence:
a small fixed aerodynamic device running fore and aft (chord-wise) on
a wing or hull, usually on the upper surface; also "deck fence" or "deck
trap," an upward extension of the sponson wall above the deck.
Flaps:
see Elevators
Fuel:
by rule, "any liquid or gas (other than air) that passes through the
intake system and/or reaches the combustion chambers(s) of an engine,"
including "oil, gasoline, Jet A, alcohol, water, and nitrous oxide."
Horizontal
Stabilizer:
loosely called the "wing," the airfoil-shaped surface mounted horizontally
above the transom and usually adjustable for trimming.
Non-Trip
Chine:
chine angled or inclined so as not to catch or trip on the water when
the boat is turning, often called simply "chine" or "non-trip."
Nose
Cowl:
the forward-most part of cowling or superstructure, a streamlined fairing;
in a rear-engined boat the nose cowl is usually an integral part of
the enclosed cockpit structure.
Picklefork:
the current three-point hull refinement in which configuration the two
sponsons extend forward of the main hull center section.
Propeller:
the device with two or (usually) three blades connected to a Shaft and
turned by the engine, thereby generating thrust from rotation in the
water; current unlimited hydroplanes employ a surface-piercing propeller;
also called "prop," wheel," or "screw."
Prop
Shaft:
propeller shaft, the rotating shaft that passes through the bottom of
the boat, connecting and transmitting power from engine/gearbox to the
propeller; generally of Monel or high-strength steel alloy with a diameter
of 1-3/4 to 2 inches.
Ram
Wing:
term properly given to the main hull center section of a three-point
hydroplane, which has an airfoil shape and generates lift by aerodynamics
and ground effects; also a secondary or tandem structure of the same
sort.
Rudder:
an upright blade that can be turned to left or right about a vertical
axis, generally mounted on the transom and extending below the waterline
to provide the means of turning a boat while underway.
Runner:
the part of the sponson bottom that serves as a planing surface, touching
the water at the lowest point.
Shaft
Log:
the fitting in the bottom of the hull through which the prop shaft passes;
also called "stuffing box."
Skid
Fin:
a vertical blade attached to the hull generally aft of the left-hand
sponson, extending below the waterline to help keep a boat from sliding
in a turn.
Slat:
a fixed or adjustable aerodynamic device mounted integrally with or
immediately forward of the ram wing to create a "slot" effect along
the leading edge; may be a canard.
Slot:
a through-deck opening or passage formed by the gap between a slat and
the leading edge of the ram wing, altering air flow; sometimes a "deck
vent." Spar: 1) the major, span-wise, structural member of a wing, a
means of attaching sponsons or canoes to the main hull;
2) the brace
between the sponsons, often covered by a canard airfoil shape.
Spoiler:
an aerodynamic device protruding
into the airstream and "spoiling" or reducing lift; usually under the
bow, such as an air dam, but occasionally topsides, such as a speed
brake.
Sponson:
the pontoon-like portion of the hull that provides hydrodynamic lift;
in the three-point configuration common to current unlimited racing
craft, one sponson is forward on each side of the main hull.
Spooge:
The name given to the excess adhesive that squeezes out during fastening or clamping.
Spoogee:
The person who applies the fasteners, clamp or adhesive.
Spooger:
The person who cleans up the adhesive after it spooges.
Strut:
1) a support or brace;
2) specifically the prop-shaft strut, a structural
member on the hull bottom near the transom, which carries the rear bearing
for the prop shaft. Stuffing Box: see Shaft Log.
Tail
Fin:
a vertical aerodynamic surface, part of the boat's superstructure near
the transom, which aids directional stability; typical current designs
employ two tail fins or uprights side by side, perhaps 4 to 6 feet apart
and slightly splayed; also "air rudder."
Transom:
the vertical structural element
or end frame that defines the aft end of the main hull or ("sponson
transom") the aft end of the sponson.
Tunnel:
1) the space or channel between the bottom of the hull center section,
or main hull, and the sponson inner walls and air traps, in which air
flow is directed and compressed by the boat's forward motion, generating
a high-pressure air cushion to partially support the weight of the boat;
2) a hull configuration that employs full-length sponsons, a catamaran-like
shape.
Uprights
or Verticals:
a common term for twin tail fins, which usually comprise upright trusses
covered by sleeves or fairings and often support a horizontal stabilizer.
Wing:
an aerodynamic surface that can generate lift; while the term is informally
applied to the horizontal stabilizer, the most important wing on a modern
hydroplane is the "ram wing."