Pic of stepped hull in action from underneath
 

The back page of Boating Magazine had an ad from Regal with this picture. I thought it was interesting since it showed how the stepped hull works from a perspective we rarely see.

Sort of makes me wonder why manufacturers don't do this for every hull to see if their design works as it should. Maybe they do but I'm not aware.

Any, I thought it'd be good to post this since stepped hull designs have been discussed here forever.

be cool to see some multi hull step pics like that...cat shots would be sweet as well!!!

Regal was showing a video that most likely that shot was taken from at the St. Louis boat show. It might be out on YouTube.

I say we get Jayboat a snorkel and turn him loose. He already has mastered the part where you go in the water with the camera gear.:evilb:

Oh snap!!:lolhit:

Welcome to the view from my world .

What about the shot of Reggies cat killer V , it's almost out the water at top speed ...how much effect does a stepped hull have
on speeds that fast ?

If you recall, Reggie also (correctly) stated that where the steps were placed on a given hull did relate to a number of other variables including how much power you had. The more power you had, the further back the steps needed to be to have any effect.

So cat killer was so fast, that wasnt a notched transom, it was the step?? :party-smiley-004:

Good one!:lolhit:

Very cool picture.

Looking at this picture, I wonder how the bigger multi-step hulls look compared to this one. Would question how efficient the prop(s) would be especially with high X-dimensions...

So the blueprint job is most important on the outer parts of the V.. I would have thought the center would have had the least airartion.. Also makes me think My side by side props, gets great air free water.. Thanks for sharing

Some thoughts or questions using the pic in post #1 as an example.

The weight of a boat is unchanged. Since part of it is riding on air it makes sense (to me anyway) that those portions not aerated are supporting the weight displaced by the air?

Is there an engineer here that can make some sense of this?

There is a bunch of vids. and pix. from Merc Racing on lake X doing the Challanger Offshore 32' and the blackhawks testings.

It helps to break the surface tension of the water to reduce drag. Would be interesting to see a cat and a double step

Excellent!!! :thankyouthankyou:

I'm in.

can you tell us where to find the vids at Lake X and the Challenger plus more vids. Is it on youtube or somewhere else. thanks

Also what month & year was this pic in boating mag ? thanks

I would think increase speed and trim angles would change the chine support load position in the water. great pic.

Now everyone can see why a depth transducer doesn't work well on a stepped hull.

Hi. Yes, that's how I see it has to work.

At speed the water supports the hull. As the hull rises and there is less wetted surface the force exerted by the water has to increase. (F=P*A) There is a reduction in the boat's weight, fuel consumption, but it's negligible.

Or cat W/triple step, I have been searching all over the net I have not found anything yet.......

Some of the weight of the boat is being supported by the bubbles.

The helpful part is that the wetted surface area of the hull is much less. This reduces the hydrodynamic drag.

The quality of water of that gives it "surface tension" also causes it to want to stick to things. A boat comes in contact with lots of water then attempts to break free of it as well.

I think the next improvement will be a surface coating that mimics shark skin

it looks like one has been invented and is going to be applied to airplanes and I think it is only a mater of time until it winds up in the marine market

http://travel.cnn.com/lufthansa-tests-shark-skin-881186

Yeah, it seems counterintuitive, but properly designed rough surfaces or ridges can help break the boundary layer of stagnant fluid off of a surface. That's the reason your radio antenna on your car and the hull of a round semisubmersible drilling rig will have a corkscrew rib running around them.

Believe it or not Shark Skin was mentioned a while back by the infamous James Darr . Very interesting .

Golf, anyone?

Where can we find these? :)

Try to get a hold off Kevin Sceba at Merc Racing or Harry Schull in Pompano Beach, FL. they might have the records. Ken Kawl, VP at the time at Merc. is retired. All my "pre June, 1994 stuff is with my "x'". Test date around late 93-early 94. (don't even remember anymore.) John Simpson (sp?)owner of Challenger Offshore at the time is gone AWOL. I can't even find him. Brownie might have some contact and misc. info. too. I have some old VCR vids the 32' (hull no. 1) with twin 502 Blackhawks running and "parked" at the Pier 33/Thunder marine 1995 Poker Run, (mayden voyage sort of speak) but not underwater.
P

what if you used a large vinyl sticker cutting machine to cut many half inch round holes. Would that be a good way to to beak up the surface and get a few MPH?