10 M triple step monohull powerboat

[Eddy Johansen]

Adam, I must then only recognize you must be the best and most experienced stepped hull designer in the world and noone comes even close to you.

So when Fountain says they spends a couple of millions developing one of their hulls and get the steps right, they could for sure save a lot just asking you how to get it right.

Or if we stay on this side of the pond and go a little north to my ol'country Norway, it is rather amazing why Goldfish worked more than a year on one of their latest developments and still ended up making new plugs and molds, delaying deliveries of several sold boats with almost one year. After making several sucessfull stepped hull designs and testing this particular model for litteraly houndreds of hours, he came out publicly and said he had to start (almost) all over again, because some "funny stuff happended in the right circumstances". Which in my opinion was the correct thing to do.

I am quite sure your designs as pretty good, so please do not get angry with me or something. I just reckon we should all be realistic about it.

NASA have spend many, many millions since 1930 or so (of course there was no NASA in 1930 , but their forerunners existed) to find the "ideal" step and some formulas on how to scale up and down. The main use for steps at that time was on seaplanes - to get them to let go of the water with as little power and as much weight as possible. It is evident that they did several findings and gained knowledge on how to make "more or less" the next model.

But there are no formulas, tricks or hokus pokus abracadabra to get it 100% right without testing. That was the conclussion NASA came to. Test it.

Basically you need 4 things to get a stepped hull right:

1. A little brain
2. Testing
3. Testing
4. Testing

If you want more examples on well known brands with lots of high performance experience, world speed records and offshore race wins that did not manage to make stepped hulls working, just let me know.

Keep up the good work!

[Ad Hoc]

For my tuppence penny worth...when one is on the edge of performance and/or design parameters, using known existing data counts for a lot, even more than on conventional boats. Everything we do as naval architects is based upon previous designs, not just paper ones, but real ones, made and tested and data gathered.

It is usually the "whole design" that is needed, not just once aspect.

I'm no stepped hull designer (just "normal" high speed), but having a vessel complete and tested and then alter the weight distribution or the weight or the drive line etc all influence the vessels performance. If the hulls remains the same, it does not guarantee the same performance, other factors come into play. These other factors all come into play for different reaosns and with differing affects. Hence the more "real" data one has one knows what really does effect performance and what does not, stepped or otherwise.

[Adam Younger]

Eddy - I'm not quite sure of your motives - I have read back through my comments on this thread and happy that I have not made any outrageous claims, comparisons to other peoples work / craft etc.

Yes - I believe very much in my work and feel passionately about it, so will of course defend my work. But I do not make un-just claims of my work or comment on other peoples work.

I agree with you in many ways with regards to testing - but the truth is that it is a luxury that many boat-builders cannnot afford or certainly not to the extent you describe above. As such we do as much testing as is allowed - and I feel as a design office we carry out a fair degree of test and development work through our own prototype / raceboats etc.