Roostertails Unlimited: [1973]
Glossary

Introduction
Ch.1 A Race
Ch.2 A Little History
Ch.3 The Evolution Revolution
Ch.4 The Principle
Ch.5 The Power Plant
Ch.6 Building a Hydroplane
Ch.7 The Crew
Ch.8 The Men With the Money
Ch.9 What's an Unlimited?
Ch.10 Preparing the Race
Ch.11 The Rulebook
Ch.12 The Spectator
Ch.13 First You Get Into the Cockpit
Glossary
Bibliography
Appendix A Unlimited Class Speed Records
Appendix B National High Point Champions
Appendix C Major Races
Air Trap — An area between and behind the sponsons which traps the air cushion on which the hydro rests at speed.
Allison — A standard Unlimited powerplant, used in American World War II fighter aircraft.
APBA — The American Power Boat Association, the governing body of all competitive hydroplane classes.
Apex of the turn — The route that a hydro driver tries to take through the turn without adjusting direction.
Back-off point — The point where a driver lifts his foot off the throttle in preparation for the turn.
Blower — Another name for a supercharger.
Bonus points — Given to the fastest boats in a race, a practice used in the 50s and which has since been discarded.
Bow — The front of the boat.
Buoy line — The line made by the buoys when they are set in a row.
Cab-over — A hydro design where the driver sits in front of the engine and which shifts the center of gravity toward the stern.
Checkered flag — Waved at the end of the heat to signify the boat has finished.
Chevy Mercruiser — An engine tried in a hydroplane.
Choppy water — The best for hydro racing, small pointed waves.
Chrysler Hemi — The auto engine used in most auto powered hydros.
Chute — The straightaway.
Cockpit — The area where the driver sits in the hydro.
Contestants’ meeting — Usually held on Wednesday before the race, to discuss rules and signals.
Contra-rotating props — Two props that rotate in opposite directions.
Conventional transom — Thick and narrow boat stern.
Course judge — He watches for rule violations on the course.
Cowling — The shell which surrounds the engine and the cockpit.
Crew chief — The head man in the pit crew.
Dead-in-the-water — When a boat comes to a stop on the course.
Dicing — The maneuvering before the start of the race.
Dove-tail — A type of tail fin, looks like no tail fin at all but uses a small spoiler at the stern of the cowling.
Driver — The person who sits in a hydro and drives it.
Drivers’ meeting — Held the day before the race, discussions of rules, etc.
Drivers’ Qualification Committee — A group that determines which drivers are qualified to handle a hydroplane.
Driving suit — The garment the driver wears, made of fireproof material.
Dry sponson — A sponson in which water cannot enter.
Dye-checking — Part of the safety precautions, the testing of the props, rudders, etc. for signs of fatigue.
Exit pin — The last buoy in the turn, the beginning of the chute.
Fan plan — A type of race whereby the winner of the final heat is the winner of the race.
Five-minute gun — Fired five minutes before the starting gun.
Flares — Set off when an emergency occurs and the race must be stopped.
Fluke — The blade of the propeller.
Fork-lift — The bow where the sponsons extend beyond the hull on either side.
Four-point design — The standard step hydro, in prominence before the evolution of the three-point design.
Gold Cup — The Stanley Cup of unlimited hydroplanes.
Green flag — One lap to go before the finish.
Griffon — A model of Rolls-Royce engines used a little in hydros.
Groove — The route the boat takes through the turn.
Guns — Fired at five minutes before the start, one minute before the start, at the start and at the finish.
Hallet drop sponsons — The deck of the sponsons are below the level of the hull's deck.
Heat — One 6-lap event on a 2-mile course or 5 laps on a 3-mile course.
Hooker — He who uses another boat to time his start.
Horizontal stabilizer — The plane that lies across the top of the tail which resembles the wing of an airplane.
Hull Balance — Very important. Determines the boat's ride.
Hydromaniac — One who lives, eats and sleeps hydroplanes.
Hydroplane — A boat that skims over the surface of the water.
Inboard sponson — The sponson that faces to the inside, left one.
Infield — That area around which the buoys are located.
Instrument panel — The plate where the dials and knobs are located for use by the driver.
Jumped the gun — Passed across the starting line 30 seconds or less before the starting gun fired. One lap penalty.
Kite — When the bow begins to rise into the air — dangerous.
Lap — One tour around the race course.
Laughing gas — Squirted into the engine for a quick burst of speed.
Life support decelerator — Helps to slow down the driver as he flies through the air after being thrown from the boat.
Lifejacket — Worn by the drivers to let them float when thrown from their boat.
Limiteds — Numerous classes of racing boats that are governed by engine size.
Lizards — The affectionate name for girls who hang around in the hydro pits.
Low profile transom — Wide and thin boat stern.
Merlin — A Rolls-Royce model engine used extensively in unlimiteds.
Messerschmitt — A German fighter plane engine tried in unlimiteds but was unsuccessful.
National High Point Standings — The standard which determines the national champion.
Nitrous Oxide or Nitrous — Laughing gas.
Non-trip — Lets the rear portion of the hydro slide sideways.
Non-trip chine — A beveled edge on the inboard sponson.
Nosing down — When the bow goes into the water.
Number one lane — Closest to the buoy line.
Official barge — The area where the referee and scorers work.
On the step — When the boat rises to sit on its plane.
One-minute gun — Fired one minute before the start of the race, all boats must be on the course and running at this time.
One-point design — Tried by a designer in 1957 but did not work.
Packard — Engine tried in unlimiteds without success.
Pickle-fork — The same as the fork-lift bow basically.
Pit crew — Those men who work on the boat.
Pit pass — Allows the holder to enter the pits.
Pitching effect — The tendency to tilt sideways in a turn.
Pits — The area in which the boats rest when not racing.
Planing — Skimming on the water's surface.
Porpoise — When the boat rises and drops drastically, or bounces.
Promoter — The group that sponsors the race.
Prop — The device that propels the boat.
Prop pitch — The angle of the prop's flukes.
Propeller Magazine — The publication of the APBA.
Prop-riding — The prop is only halfway in the water.
Prop-torque — The effect of prop-riding, a constant left turn.
Qualification ladder — The order in which boats may make qualifying attempts.
Qualify — Turn laps at 95 m.p.h. on a 2-mile course or 100 m.p.h. on a 3 mile course.
Quill shaft — A thin rod that connects the blower to the power unit, the cause of many breakdowns in the past.
Race committee — The organization that operates the race.
Racing trim — As it is when it races.
Referee — The absolute authority on all matters concerning the rules and running of the race, the APBA supervisor.
Rolls — Engines made by Rolls-Royce, usually means the Merlin.
Roostertail — The high plume of water behind a hydro at speed.
Rudder — The device that causes the boat to turn.
Safety belt — Not allowed in an unlimited hydroplane.
Sanction — The right to hold a race.
Sandbagging — Purposely going slow for one reason or another.
Shutdown — to decelerate.
Shutdown buoy — Same as the back-off point, usually.
Signals — Communication between the boat and the barge.
Skid fin — A blade that holds the boat through the apex of the turn.
Spilling air — Letting the air cushion go to get better control, especially in the turn.
Spoiler — Any device that disrupts the flow of air.
Sponson — On each side of the hull toward the bow, the members that resemble pontoons and on which the boat rides.
Sponsor — The business or person who helps pay for the boat's campaign.
Stack — The exhaust pipe.
Stack fire — A fire on the exhaust pipes.
Standard bow — The rounded nose.
Starting clock — A black-out clock that tells the time before the start of the race.
Starting gun — Fired at the beginning of the race.
Starting line — Opposite the official barge, where the boats start.
Steering wheel — Used by the driver to turn the boat.
Step hydro — Used many years ago, same as the four-point design.
Stern — The rear of the boat.
Sticky water — Smooth water which saps power from the engine and does not allow enough air in the air trap.
Tail fin — At the stern of the boat to stop it from bouncing from side to side.
Tandem-mount — Engines placed one in front of the other.
Tenders — Small boats that do various duties on the race course.
Three-point suspension — The basic design of hydros today, the boat rides on three points.
Throttle — Causes the engine's speed to alter.
Thunderboat — A metaphor denoting Unlimited Hydroplanes.
Top speed — The fastest speed obtained on the chute.
Trailer — The device that carries the boat on land.
Transom — The flat surface of the stern.
Trim-tab — A spoiler located on the tail fin to offset prop-torque.
Turbine — A type of engine, roughly the same as a jet engine.
Turbo — Short for turbocharger.
Turbocharger — Performs the same job as a supercharger but uses power from the exhaust.
Turn buoy — Where the driver begins his turn.
Unlimited — A class of hydroplane not limited in engine size.
Unlimited Racing Commission — The body that awards sanctions and recommends rule changes for Unlimiteds.
Walk — When the boat hops from sponson to sponson.
Walk the stern — A slight turning of the boat before the rudder is moved, in perparation for the corner.
Warm-up speed — The speed ideal for warming up the engine before the race.
Washed down — When a boat is caught in another's roostertail and the engine quits as a result.
Water condition — Whether the water is choppy, sticky or rough.
Waterline length — The distance between the tip of the bow to the tip of the
Wet sponson — A sponson in which water is allowed to enter.
Wheel — A propeller.
White flag — Signifies the period between the one-minute gun and the starting gun.
Yellow flag — Signifies the period between the five-minute gun and the one-minute gun and when there is a hazardous condition on the race course.

(Reprinted from Roostertails Unlimited by Andy Muntz, 1973)


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Leslie Field, 2000