Question: How do you drive an Unlimited hydro plane. Answer: Very carefully
It’s changed a bit, since the old days when Bill Muncey, the Mario Andretti of boat racing, used to say that. Then, the Unlimited hydroplanes the thunderboats brought to mind what they used to say about sprintcars or the Granville Brothers’ Gee Bees: ‘Never forget, given half a chance these things will try and kill you.’ Muncey knew that all too well, for he had suffered countless accidents in which internal organs were forcibly, if temporarily, placed in an orientation that was not in accord with Nature’s intentions. More than once he was listed dead on arrival at hospital. “Anything other than death,” he once said, “is a minor injury.”
The new breed of turbine-powered, carbon fibre hulls are less unforgiving than the old Rolls-Royce or Allison piston aero enginepowered wooden boats of yore. In the last 10 years, as qualifying speeds have nudged beyond the 170mph lap, safety has progressed at a similar rate. An Unlimited is around 30 feet long and up to 14 wide, and at speed rides only on the hub of its three-bladed propeller and the tips of the two sponsons either side of the driver’s shoulders. The spectacular roostertails, which comprise hundreds of gallons of water, are thrown up by the propeller on the straights, and by the propeller and skid fins in the corners. Intriguingly Ron Jones Jnr, who has followed in the wake of grandfather Ted and father Ron as one of the leading designers, has talked of a form of active suspension to further optimise the aerodynamic pitch of what is effectively a wing that flies over the water.
The Unlimiteds produce upwards of the supposedly mandatory 2650hp, and they need all the power they can get. The 8.3-litre automotive V8s in the Grand Prix boats which supported the Gold Cup made a fantastic sound, but when you watch them on the course you soon become aware just how much power it takes to drive a propeller through water. Today, Ed Cooper Jnr and Mitch Evans plough pretty much a lone furrow with piston power, and their efforts have created the fastest Allison-propelled craft in history. Their lap record of 149mph bears testimony to that. Yet against the turbines the Miss DOC RayBan faces insuperable odds.
The turbines have lost the thunder that made the Unlimiteds so famous. Miss Budweiser leaves the jetty with a whine and a raucous cough, and a delicious stench of Jet A kerosene. On full noise she sounds like the wind screaming round a very tall building. These boats are literally waterborne aircraft, utilising aircraft technology and even their windscreens. Most of the safety cell canopies originate from F16 fighters, and combine with massive internal rollhoops to offer the drivers levels of protection their predecessors could never have imagined. There are skidfins, and then there are skidfins. These are massive steel plates mounted on the back of the left-hand sponsons, to help the boats get bite when cornering. They are adjustable, and withstand some 18,000lbs when the drivers keep their right feet hard on the throttles and pitch their craft into the turns. “Imagine dropping the 6000lb Miss Budweiser from its crane, some 20 feet to the ground, and that’s the sort of force you’d be talking about these fins having to bear,” says Stan Hanauer, Chip’s father.
So what are the new boats like to drive? 39 year-old Steve David mixes a real estate business with an obsession to race boats that started when he was 12. A veteran of literally hundreds of limited class victories, earlier this season he finally made the Unlimited breakthrough to win Sneaky Pete’s Texas Hydrofest opening race in Lewisville with the Miss T-Plus. He is our guide.
“There’s a six-point harness that straps you in, you’re hooked up to compressed air in a bottle just like you’re scuba diving. Starting a turbine is really just electronics, unlike a car. You switch on for ground idle, then flick on the 24/48 volts, open the fuel and the turbine spins up to 42 per cent and lights up, then once you are away from the dock and have the boat pointed where you want to go, you accelerate. You don’t need the throttle all the way to the floor, but you give it quite a lot of fuel to get the boat on top as we say, on the plane. “When you start there’s three igniters in the back of the turbine that ignite the fuel, and if you take a good dose of water down the intake when you’re trying to get on top, it puts out the fire! You need to relight it and go again. That doesn’t happen once you begin to break loose of the water, at about 90 miles an hour. In reality, you’re not totally free of it until about 120 miles an hour. That’s when you’re actually up on the sponsons, getting a decent ride. It might seem kinda quick, but that’s just idling around. In my 1-litre Modified I’d be on plane around 50-55; in my 7-litre at 80, because they were lighter.
“If the boat is set up right there’s very little torque reaction down the straight. All the turns are to the left, like Indy, and when you go into one the boat very much wants to go to the infield because it’s set up with offset, one sponson wider than the other. You need to hold it a little so it doesn’t go in too much. It’s interesting; the faster the turn, the wider the turn, the more it wants go into the infield. The tighter the turn, the less it wants to. Those are the only times you’re really fighting the wheel. If you have to fight it on the straightaway something’s wrong, you’re bleeding off speed. “We have huge skid fins on our boat, but they’re shallow and long. The boat doesn’t really notice length of fin, but it definitely notices depth. Different drivers have different styles in cornering. Some, they’ll come in and they’ll be perfectly straight and just launch the boat in so that the fin’s got good bite in solid water. Others, way before a turn they’ll turn the rudder and set it up like that, in a slide. In the Limited boats, where horsepower really is limited, you want to set it UP in a nice arc so you maintain speed all the way through. In an Unlimited there’s so much power it’s not so critical because a turbine doesn’t bleed off the speed that way. I’m still somewhat using my style from the Limiteds.
“Here in Detroit the first turn is wide, 1400 feet, but the second is real tight, only 600. You really need two set-ups, and you need to take advantage of the big turn and maintain speed all through that. Take a good line on that turn, you’re gonna be real close to your max coming out. You then come down to the second turn at around 198 to 205 miles an hour. You’re still wide open, but you bleed off so much you’re coming out at maybe 125. The only time you’d have to lift is if the boat’s too light and the fin’s not in the water. If you sense you’re out, you either have to operate the left-foot pedal to activate the canard fins at the front to increase downforce and bring it down, or if that doesn’t work you have to get out of the throttle a little. The trouble with a turbine is that if you do get out of it, it takes so long to build it back up. It’s just like a turbocar, you gotta keep the boost up. “The canards are set so that if you take your foot off the pedal they automatically reduce downforce and drag and return to the neutral position. You set the rear wing depending on the course. You can build rear-end lift to keep the nose down and the prop free. On other courses, say where the temperatures are very high and there’s hardly any air density, then we’re gonna change that wing, to make the boat fly a little bit more.
“The worst part here in Detroit is by the Yacht Club just before the second turn. There’s always wind there and you need to keep that fin in the water otherwise you’re not gonna be able to bury that left sponson in the turn. You’re always working the canards here.
“The actual racing is a lot smoother than you might think, because if your propeller is riding in someone else’s wake you’re just finding air. You need to turn water!” In nine out of 10 races qualifying decides lane draw from a jetty start nowadays, but like Indianapolis. Detroit clings dear to tradition. There drivers mill around watching a vast clockface by the startline, timing their approach so that they cross at exactly the right time and have free lane choice. Cross a second early, and you’re penalised a lap. A lane is’ the width of a boat plus 10 feet, and you must be five boat lengths ahead before you can claim a lane. With rearward visibility severely limited by the roostertails, drivers rely heavily on radio messages from their crew. “Most of the guys are real clean,” says David. “The boats are dangerous enough without having to resort to dirty tactics like washing a guy down with the roostertail.” D J T