I was watching it too. At first the graphic showed 2 props (both spinning the same way?!?) Then they showed the graphic again, and it showed 4 props. It was pretty weird for sure. And no, I'm not drinking.

From what I understand is the props are intentionally indexed to have one blade from each side alternate to provide even thrust and balance torque so that the boats leaves and fly straight.

Lapse, if you are speaking of Unlimited Hydroplanes we run one prop, max. diameter of 16", 3 blades and any pitch. Most of us are using T-55L7-c (Lycoming turbines from Chinook helicopters) , although virtually any recip engine is allowed and other turbines are welcome that have been dynoed and have similar torque and HP to the T-55L7-c. One of our competitors, the U-3 runs a 1710 CI V-12 Allison aircraft engine, from the P-38 Lightning days. With turbo and alcohol it's about 3000 HP. This is within 100 HP +/- of the turbines, however the recip engine has no weight restrictions. They are about 5500 lbs. race ready and we must be 6,750 lbs race ready.

Steve
U-6 O Boy Oberto

Here is a link to some video's,

http://www.dragboats.com/video/video.php

I too, thought you were referring to the Unlimited Hydroplanes not the drag hydros. Have a lot of experience working with the rescue crews at the Detroit Gold Cup in the past. I'm on the rescue boat in the 3rd photo of the Jasper engines incident below:

Boy that sure looks like fun, upside down and backwards at 200 mph.:D

PeteB's video links include 2006 National pick with Kutz leaving the line and flipping over backwards. Its the one described as having too much HP. Any way if you pause it while its up side down you can see the twin drives and single rudder.