PWC Hull modification question
 

Hi Guys,

New to the group, but it seems like this is a place with enough
expertise to answer the question I have. I'm attempting to make an
aqua-trailer for camping and exploring behind my personal watercraft.
Something similar to this http://www.hydrotrailer.com/index.html .

I don't want to spend 800 dollars on one of those or have to track one
down, so I want to make my own using an old fiberglass jetski hull. The
hull I'm starting with is an older standup jetski hull about 6 feet
long, similar to this http://www.bearlakefun.com/sxi1.jpg .

I've got a couple questions for those of you knowledgeable about
fiberglass and hull design.

1. What should I do with regard to the rear end of the ski? It's pretty
much 90 degree vertical at the rear end, which works fine when it has a
motor powering it, but will this create drag or instability when towing
it at planing speeds? Would rounding it off in the rear so that it's
more bulbous be a more stable or efficient design?

2. What should I do to the current coating/paint on the jetski hull to
properly fiberglass it? Sand it down/off until I hit smooth glass I
would assume, but if aesthetics aren't really that important, would the
bond be strong if I epoxy the glass on top of a roughed up topcoat?

3. Any suggestions you guys have to make this thing more stable and
efficient when being towed behind at 30-40 mph? I would think flatter
is better in a planing hull behind a craft that is breaking and
smoothing the water in front of it, but I also don't know much about
hull design. Since gas mileage is a factor of how far I can explore,
the less drag that this thing (~300 pounds loaded I'm guessing) puts on
my watercraft, the better. Let me know if you have any ideas.

Thanks so much guys, I welcome any and all responses

Chris D.

Austin, Tx

PWC Hull modification question
 

You have asked an interesting question.....I think the best start might be
to try towing your or another pwc to see how it behaves on different length
lines. Slow speed to start until you see how it goes. You may also want to
consider an old tender for trials.

Dave

PWC Hull modification question
 

I think you've got a pretty good idea there.

I'll leave the fiberglass questions to others, but as far as the
stability when towing, You might consider adding a skeg in the last
quarter of the "trailer". Should keep things all lined up and travelling
in the same direction as the tow vehicle.

Also, remember that your spray will be hitting this thing square in the
face. Plenty of gaskets on the door would be a good idea.

Chuck