Any disadvantage to steps?

[johndmay]

I think I know the advantages, (More air under the stern=less friction=more speed)
but are there any disadvantages? Do they effect handling at WOT? Are they only effective on boats over 20 feet? Who first used them on production boats, and when? Is it possible to have them cut into an existing hull, such as my '88 Z-25? Would it be worth the expense?




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John D. May
Manotick, Ont.
www.jackmay.com

[Frank Civitano]

The Step hull has one flaw? Handling on turns, When making a turn instead of trimmig down to put your nose in, you have to keep the boat trimmed up to the nose from digging in. The only problem with this is your boat runs a lot looser then a straight bottom. Once you master a Step its great. The step has been around for a long time but the man that mastered the step was Stephen Step Velocity boats. Now every boat company is turning toward steps. One man that is very good with the Step hull technoligy is Steve Simon? (Donzi) As big as the 38zx is she moves at speeds over 80mph. Ventilated hulls add air, Thus more speed. Now your hull is not made for a step, a stepped hull is designed in ? Not cut in your strakes are not designed for the step either, Steps add about 5mph depending on the boat.

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Frank Civitano

[Barry Phillips]

John: Steps have been arround scince the
1930s and before, Garwood used them on
his gold cup boats. The steped hydros
evolved out of this error. Modern hull
bulding and CAD design has made steps
more practical for pleasure boats. I
am amazed at some of top speeds that 18
footers like Bayliners are making with
V6s because of this technology. There
was a great article on step hulls in
Trailer Boat last year, pros and cons.
The main advantage is great top speed
with smaller motors. I am reading test
on 18 and 20 footers with V6s and 305s
running in the 50 to 60mph range, wide
beamed family bowriders and cuttys.
The article pointed out that trailer
loading can be compromised because
the step can get hung up on the bunks
or a roller, another opinion was that
on shorter hulls when aired out, can't
tke advantge of a step built into a midships
because this part of the boat is out of
water anyway. Another con was prop cavitation
and hooking in a turn without proper trim angle, per Frank's comment. The article did point out that the cons can be overcome with carefull design, also the Donzi Daytona was one of the better stepped designs out thier. I think that the ventailed ports in the strakes used on Phamtom boats is
useing is really interesting. Scince
the Classic Series Donzis use traditional deep vees, I well stick with that, but step bottoms are here for good and can only get better and faster.

SO-SLO

[seano]

Frank,

I thought George Linder(Shadow) was the first to incorporate steps in a offshore catamaran and Paul Fiore(Hustler), on a "production" V-bottom...although I coud be wrong. I had a 1981 30 Shadow Cat---#2 out of the mold and I thought Paul was building the 40 Fiore with a sigle step in the early/mid eighties? I could be misinformed...when did Steve put steps in his Velocity?

[Frank Civitano]

Seano, I remember Powerboat magazine doing a piece on Stephen Stepp back in his hayday of racing. He was the first to incorporate the mid step in a racing deep V. This was before his Velocity days, Thoroughbred boats. This is when I started getting interseted in Step bottoms! Hustler and Outerlimits are known for there Step pads in the rear of the boats and are a great inovation! Outerlimits just added a feature to there mid step, a ventilated step getting air off the top of the boat through a scoop and sending the air under to the step for added lift? I saw that design this weekend on a 42 Outerlimits, Mike Fiore design. When Steve Simon designed the step for Donzi They were Deep, Now that I added more HP to my 22ZX I can really see the advantage of step. Now when I'm running a 2-3ft chop instead of banging at 60 I pocket over the waves at 75! What a feeling. During the Poker run this weekend I had Phillip Galletta (HotBoatMagazine) on my boat. He loved the ride he couldn't believe how That little 22 blew off some of the bigger rigs in choppy water! He loved the ride so much, He put his wife on another boat that he was supposed to go on and came back with me! Now thats the power of a Donzi. Your right about the cats They used steps for better lift and stability , I'm surprised it took this long for a V hull to get stepped. And this is just the beginning! Remember when 50 was fast? Know the goal is better then 120 in a vhull. Don would be in his glory if he was still alive.

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Frank Civitano