It is set to be a weekend of thrills on the water with two sets of powerboat racing on the harbour.

Starting at 11am on Saturday the GJ Gardner offshore power boat series racing will hit the water while the hydroplanes hold a two day regatta on the water opposite The Strand.

Konica Minolta testing the Tauranga water.

The ocean racers are on a course down the harbour, up the Western Channel and back down the Otumoetai Channel. Shore based spectators are advised the best views are from Sulphur Point.

The hydroplanes are racing on the upper harbour. The NZ Grand Prix event is being held over two days off The Strand, once again offering close up views of loud boats going very fast.

The offshore racers mixes big and small boats on the same course which means the co-driver is kept busy, says Shane Rumens, the co-driver on the Konica Minolta boat.

It is the 200hp outboard class, where a stock standard engine is installed on a small hull.

They are racing four boats in the series, but hope to contend with four or five day entries at each race.

'We will still race against them, it's just not for overall points,” says Shane.

'They can just come along and have a bit of fun. It's good close racing, especially for the locals point of view.”

The class has a top speed of about 75mph or 120kmh.

'It's a liquid race track with no brakes. For my job as co-driver I am forever looking around.

He's looking through the spray for the competition and the big boats.

'The cabin boats they can't see a lot and they are going twice as quick,” says Shane.