kevinle

Hi, with the same set up, which gonna be faster between hydroplane hull and catamaran hull? and how faster?

Flabum

you can't run the same setup on both boats, but if you ran the same engine in both boats and the boats were of the same length, the Hydro should be faster, it simply would have less hull in the water.

Alex73

Fisrtly i think a cat is a hydroplane. The hydro would be faster on flat water but wont handle well on chop.

i would vote cat as i love them.

Hydro Junkie

Sorry, but a cat IS NOT a hydroplane. A cat is a deep vee that was cut in half and had a tunnel put into the middle. It is a planing style hull that runs about half it's length in the water at full speed. A hydroplane is a wing with aerodynamic floats on eash side. At speed, less than 20 square inches of sponson bottom, the prop, rudder and skidfin are in contct with the water

Now, lets look at the full sized boats and how they are raced. A cat is normally run in the offshore races in fairly choppy water(normally over 18 inch chop) for distances in excess of 50 miles. A hydroplane is raced on an approximately 2.5 mile oval on an enclosed body of water for a distance of 10 to 15 miles. Any chop over 12 inches can be damaging to the boats.

Lets look at speeds. A cat will run in the 80 to 100 MPH range with usually two 1000+ hp V-8 engies while an Unlimited hydroplane will run in excess of 200 mph with one 2700+ hp turbine or Turbo Allison V-12 aircraft engine.

Now, looking at the R/C boats of equal length with similar engines, on flat water the hydro will run away from a cat in both a straight line and a corner. On choppy water of 3" waves or more, the cat will eat the hydro for breakfast

jdoug

Alextitchmarsh - I agree, a cat IS a hydroplane.

Hydro - Are outboard tunnels hydros? Yep


I would consider a hydro to be any boat that when planing, is held up by a cushion of air. (Cats, tunnel hulls, pickle fork and round nose hydros)

Back to the point...I would agree with everything else.

piper_chuck

My Feedback: (12)

NAMBA and IMPBA both categorize cats and tunnels as hyrdoplanes. They're certainly not 3 point hydros such as the 1/8 scales, sports, or riggers, but they are usually considered hydros.

misshydro

Depends on what water you run,But the cat is better then hydros.The cats are universeial,they can run on choppy and smooth water.A hydro cant. Hydros are comciter a hydro too,thats What I was told when a little girl.My uncle had a guy who'd live accross the street from his garage and he'd race the old shove nose hydro front motor one.So I'd went over there when he'd worked on it,to say this it was a blast!!!

Hydro Junkie

I now they are catagorized the same by the sanctioning organizations, but it still doesn't make a hydro, a tunnel and a cat the same. They are very different boats designed to do very different things.