Hydro dynamo

Chris Beattie | VOLUME 30, ISSUE 2
GP1 at speed. At full throttle it is capable of over 280km/h. If things do go wrong at hydroplane speeds, they go wrong in a hurry.
Victorian powerboat racer Grant Harrison is set to defend one of the oldest trophies in sport when he takes on all-comers for the EC Griffith Cup.

Not many people reckon they can tip-toe across the water at nearly 300km/h, but I know a bloke who’s done it. The only trouble is, there’s not much of a margin for error and if things go wrong, the consequences aren’t worth thinking about.

Grand Prix hydroplanes are the ultimate machines in the powerboat racing scene. At speeds close to 280km/h a GP hydroplane relies on two tiny contact points on the water roughly the size of a 20c piece at either corner of the sponsons at the front of the boat. A very rapidly spinning propeller at the back is the only other part of the boat in the water – and then only half of it is underwater if the hull is behaving itself. It is a very, very delicate balancing act that takes skill, bravery and a degree of luck to maintain.

The idea is that the less time the hull spends in contact with the water, the less friction or drag it has to deal with and the faster the boat goes. The flipside is that there’s a very real risk that the boat will lose contact altogether.

Complicating the scenario is that there are likely to be several other boats rushing around in very close proximity, all vying for the lead. Visibility is hampered by giant 50m high walls of water called ‘roostertails’ and waves and wakes can make life in the cockpit interesting, to say the least.

If things do go wrong at hydroplane speeds, they go wrong in a hurry. Boats can instantly turn into planes and this is where the downside of gravity comes into play – literally.

A hydroplane landing is never pretty and in the event of a ‘blowover’, in which the boat flips in the air, it returns to the water upside down, invariably at speed and inevitably in a shower of very expensive shrapnel. The effects on the driver are usually on the wrong side of severe.

Victorian businessman and multi-championship-winning GP hydroplane racer, Grant Harrison knows better than most how bad it can get. A few years ago he went from hydroplane driver to pilot in a split second while on a test run (see Sudden impact sidebar).

He has had a couple of other close calls over the years, but like most racers, the urge to compete keeps him coming back for more. And ‘more’ in his case is actually quite a lot.


When I visited him at his Melton Toyota dealership on the western outskirts of Melbourne in mid-March, 2015, he was preparing his boat, GP1 for a hectic racing program over consecutive weekends, culminating in the EC Griffith Cup, an annual trans-Tasman contest that could more accurately be described as a feud between Australia and NZ’s top hydroplane racers. It’s a contest with a lot of history that goes way back to 1912, when Sydney boating identity, Charles Earnest Griffith donated the cup, beginning more than 100 years of trans-Tasman rivalry on the water. The winning country also has host rights and Australia has been in possession of the cup since 2012, when Harrington brought it back to Australia.

Grant has won the cup four times and his father Keith, himself an accomplished powerboat champion, has managed to snatch it from the Kiwis once as a driver and five times as team owner. Grant also managed two world titles, being awarded the UIM World Grand Prix Hydroplane Championship.

The Harrisons are actually somewhat of an institution in the sport. Keith campaigned a series of boats in the heydays of powerboat racing from the mid-’60s through to the early ‘90s, notching up a cabinet full of trophies and championships along the way. He was inducted into the Australian Power Boat Association Hall of Fame in 2007 and is a Life Member of the Melbourne Runabout and Speedboat Club.

As team owner, Keith is still very much an active participant in the family race operation, the 73-year-old former car dealer building and maintaining the engines for GP1, the high-tech missile that Grant has been campaigning for the past seven years.

Despite the fact that Grant is dealer principal of one of Australia’s most successful Toyota dealerships, he’s very much hands-on when it comes to preparing GP1 between races. A qualified mechanic, the 45-year-old takes care of various maintenance chores, working nights on the boat between races and usually reinstalls the engine after Keith has given it the once-over.

In recent years the Harrisons have dominated the sport with a boat that is equal to the best in the world.


The 7.3m all-carbonfibre, twin-sponson hull for GP1 was designed and crafted by team member Grant Rollason at Harrison’s dealership maintenance facility, commonly referred to as ‘the shed’, but which might more accurately be described as the ultimate man cave for diehard petrolheads. Inside is a treasure trove of hulls, engines and other bric-a-brac collected over two generations of racing. There are also stark reminders of earlier mishaps, with shattered sponsons and tortured bodywork all that remain of GP101, the boat all-but destroyed in Taree.

Long-time team member Geoff Sheldrake is drafted into the side as needed and is a critical player in pre-race boat prep. In a lifetime of working with engines, including alongside legendary Australian engineer Phil Irving, Sheldrake teamed up with Keith 40 years ago and is relied upon to take care of the more technical aspects of the operation. Filling in the gaps on race day are Grant’s uncle, Geoff Harrison, cousin Glenn, otherwise known as ‘Terra’ and Paul Morrow.

Anyone who has ever heard and ‘felt’ a GP hydro run knows it takes a big motor to reach the enormous speeds they are capable of. In the case of GP1, a massive 510 cubic inch (8.3lt) Chevrolet-based, supercharged big block V8 resides just to the rear of the cockpit. It is crammed full of special racing hardware and is force-fed a diet of methanol race fuel that helps it achieve in the vicinity of 1600hp.

The engine drives through a compact gearbox to a shaft that is fitted with special racing propellers that can cost upwards of $5000 – but even at that price they have been known to fail, sometimes catastrophically. One let go on GP1 in a very early race, costing Grant a certain EC Griffith Cup and causing serious damage to the rear of the boat.

At most meetings the team takes a spare engine as races can be punishing on mechanical components. An engine swap takes around 20 minutes.


When it comes time to race, Grant is strapped into what is referred to as the ‘capsule’, a fully-sealed cockpit designed to protect the driver in the event of a crash. Danger can come from any direction as collisions with other boats are not uncommon. Grant has had a spinning propeller carve holes in the deck and knock off the mirror of his canopy only centimetres from his head when Spellbound, an earlier Harrison team GP hydro, was hit by another boat in 2001.

A multi-point harness holds him in place and he wears a military-spec Top Gun-style helmet with a separate air supply and radio comms builtin. There are two pedals at the front; the right one for the throttle and the left to control the angle of the front ‘canard’ or wing as it’s sometimes known.

This is a critical element of the boat’s handling and controls how the boat sits at speed. If Grant feels it’s getting a bit ‘loose’ he can adjust it during the race to lower the hull.

In the floor is a large red lever that activates an escape hatch in case the boat is upside down. So far on GP1 at least, it has not been used in anger.

At the rear is a large stainless steel rudder, mounted to the hull with industrial-strength brackets and hardware to withstand the enormous forces encountered at race speeds.

On GP1 there is a second fixed ‘rudder’ or fin mounted to the left side of the hull next to the driver’s compartment. Its function is to aid turning and take some of the strain off the driver as he struggles to turn the wheel at speed.

In principle, hydroplane racing is similar to NASCAR (turn left, go fast, repeat), with boats racing anticlockwise around a course up to 1800m in length, with buoys marking the turns at either end.

But while it sounds relatively simple, there is more than enough to keep the driver occupied, particularly as speeds climb.


“At lower speeds the boat is pretty stable, but around 160mph (260km/h) it really livens up,” explains Grant. “And up around 170mph (275km/h) you’re really in unfamiliar territory. The slightest ripple in the water can unsettle the boat and at these speeds you really know you’re on the edge.

“The faster you go, the more the boat lifts and at 160 or so it feels a lot lighter. It might only lift another inch, but it means there’s a lot less boat in the water and you’re really just floating on air. That’s when the blow-overs can happen.

“I’m really still learning every time I take the boat out and, without blowing my own trumpet, I’m one of the most experienced GP hydro drivers around.”

Anyone wanting to see Grant and the various other racers in the multiple Australian Power Boat Association classes in action should head to Lake Eppalock in central Victoria on April 24 to 26, 2015, when GP1 will defend the EC Griffith Cup on a weekend packed full of high-speed racing

Sudden impact

“I was giving the boat one last high-speed run to check it out in a early morning test session before pulling in,” says Grant Harrison of the incident that very nearly cost him his life in Taree, NSW in 2005.

At the time, we were watching amateur video footage of the crash that destroyed GP101, the predecessor to GP1 and almost ended his career.

“I don’t actually remember the crash or being upside down, but we reckon I was doing around 155mph (250km/h) at the time and the boat just took off and cart-wheeled through the air. It came down upside down into the water. It turned out the rudder had come off the boat when it hit some debris. From there I had no control.

“It absolutely smashed the canopy and ripped my helmet off with the impact. I was lucky that one of the rescuers on the course had watched earlier in the day when we’d shown them how the steering wheel comes off, because they wouldn’t have been able to pull me out otherwise.

“They dragged me out from the escape hatch in the floor. I was unconscious and my lungs were full of water, but they worked on me all the way back to shore and I was flown to Sydney and put in an induced coma.”

The next thing he remembers is waking up in hospital in Sydney four days later, bruised, confused and very, very grateful to be alive.

“I broke my C1 vertebrae at the base of my skull and a specialist said I came within a millimetre of being paralysed from the neck down.”

Within two weeks Harrington was back at work with no memory of the crash that almost took his life. An enforced two-year break from racing followed as GP1 was built for a renewed campaign.

“I’m probably a little more aware now when the boat gets loose, but because I’ve got no memory of the crash it hasn’t really affected my racing.”