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View Full Version : A different Genesis question about the hollow pockets under the rear transom.



1945dave
08-16-2012, 12:22 PM
Anyone ever fill in the hollow pockets under the rear transom area. I can tell you the real Mystic 50's do not have this hollow area and I don't understand why they are there. Perhaps it does not matter but they bother me. Yes these pockets are above and to the rear of the riding surface of the sponsons but as the boat bounces and hops I figure these pocket have to come into play at some point. I am thinking about filling in this area with a light foam filler. Any thoughts? I have notice some other model cats have something similiar, why? I don't see this as a needed item in the molding process so why are they there?

Dave

Fluid
08-17-2012, 07:24 AM
The "pockets" are there for mounting some stinger struts which attach to the hull where the "pockets" are placed. The "pockets" do absolutely nothing as far as air flow etc. is concerned - there is no need to fill them but if they bother you, by all means fill them.



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Rocstar
08-17-2012, 09:09 AM
I'm not sure what the alternative to the "pockets" would be....a solid 2'' thick transom? Also don't understand what you mean "come into play" as the boat bounces. I don't think there is any negative effect to the open space...

HYDROJERRY
08-17-2012, 09:56 AM
I agree with you Dave and mentioned something about them when i got my Genesis along time ago, seems like they would just catch the water and create drag like a pairashoot,,, maybe you could just sand the sides and rear section down to meat the actaul hull, i wouldnt think that they are hollow,, then it would actaully bring the underside of the transum up wich would be even less drag i would think!!! Hell i may try it myself!!!!

Rocstar
08-17-2012, 10:00 AM
I misunderstood what "pockets" your were referring to Dave, sorry.

I assumed they were there for twin stinger clearance....maybe it was an afterthought on the hull design.

1945dave
08-17-2012, 10:57 AM
I agree with you Dave and mentioned something about them when i got my Genesis along time ago, seems like they would just catch the water and create drag like a pairashoot,,, maybe you could just sand the sides and rear section down to meat the actaul hull, i wouldnt think that they are hollow,, then it would actaully bring the underside of the transum up wich would be even less drag i would think!!! Hell i may try it myself!!!!

The transom design on the Genesis is true to form copying the real Mystic 50's design other than the pockets. The aerodydnamics are intentional. The extra area behind the basic hull has to do with added floatation in the rear reducing rise upon acceleration and also allowing the boat to handle the weight behind the cg at slow speeds. To suggest the pockets do not come into play on our model can not be logical if you think about it. I am not saying that without the pockets the Genesis would run faster or turn better. I do believe however, that the pockets do affect acceleration and add a jerky type of drag that is certainly not a good thing. If my intention was to go after some record using the Genesis I would surely believe doing away with the pocket would be needed.

Regarding sanding or cutting off the extended portion of the transom to the rear of the riding surfaces, that would make the Genesis just another cat. As beautiful as the Segad, and the Aquacraft Mystic hulls are they are not close to approximating the real 50 foot Mystic, which the Genesis does better than almost anyone else. Fighter Cat and the Daytona do as well. I repeat. The $2,000,000.00 full scale Mystic has this transom design for a reason and it is not just cosmetic.

Dave

Fluid
08-17-2012, 02:34 PM
If my intention was to go after some record using the Genesis I would surely believe doing away with the pocket would be needed....Not at all.
I set several SAW records with an Apparition knock-off cat - it had those "pockets" and they certainly did nothing bad to the boat. The water does not touch them and the air is in severe turbulence under the overhang anyway. Too, the boat would probably be faster without the overhang - all my other record-holding cats had no overhang. Knock yourself out, but full-scale design practice often does not transfer well to models......



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1945dave
08-17-2012, 04:25 PM
Interesting Fluid, thanks for your input. I agree that comparing models to full scale is not the easiest direct comparison many would believe. A good friend of mine is a marine/aeronautical engineer that has been working for almist 6 years on a 50 foot cat design built just for the purpose of breaking the SAW record currently held by Miss Budweiser of unlimited hydro fame. This cat is designed to run over 240 mph. I showed him the Genesis model and the pockets and he smiled in a knowing kind of way shaking his head. In the full scale world nobody broke the 200 mph barrier until the over hang with a taper was factored in. The details that go into designing a boat of this type is incredible, This boat is already over 4.5 million dollars. Still, I am ready to declare this subject closed. The pockets may not be all that important but I still want to know why they are there? If they are really there on purpose for the possible mounting of dual stingers great but I have my doubts. It would seem logical to believe that they are molded in on purpose but why?

Subjecty closed.