After today, it's on to the semi-finals. The Metal Medics are pitted against the Art Attack in a watery challenge. The teams have ten hours to build a powerboat. The boat will have to be fast, maneuverable and able to carry two people...a pilot and a passenger. The teams will sail their boats from a floating dock to an island where they will have to pick up one teammember and take them back to the dock. The first team to "save" all of their teammembers wins.

Each team has a different design idea. The Metal Medics are going for a "trimaran" design. A long tube with a pontoon on each side for stability. Since they'll probably use oil drums for their boat, they'll need a big engine to push it through the water. It won't be the sleekest but it will be fast. The longer your boat, the faster it will go. The other name for this type of vessel is a 'displacement hull' boat, so named because it displaces a lot of water. Weight and stability will be their major issues.

The Art Attack, on the other hand, will be doing a somewhat more traditional design with a "planeing boat". Their boat will be low to the water and be quite wide. The idea will be that the more speed they get up, the boat will rise up and skim along the surface. It's the same principle as a water skiier. As the skiier gets up to speed, the tips of the skis come free of the water and he only rides on his heels. They'll need to worry about staying afloat.

Art Attack clockwise captain Kim, Dwayne & June their expert is Justin Manley	The Metal Medics bottom, l to r; capt. Dr Bill, Alex & Bob top, expert Larry DeCamm
Those oil drums will create a lot of bouyancy	A motorbike will provide the perfect lightweight engine
Doesn't that van look familiar? The Brothers in Arms used it's back axle in the dragster competition of Series 3 (see inset)	Why do teams always use heavy Range Rovers for water machines? Probably because a diesel engine won't cut out if you get it wet.
A real powerboat	Our judge is Frank Ayreot
A pre-made boat	That pontoon will provide stability
A massive diesel engine	An enemy in the camps!
Cathy & George relax	What the hell is that?
Always time for a spiffy paint job	Making the bow a bit smoother
Look at that baby spin!