Boat Forum / Building / August 2006

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.
crdpoker@yahoo.com
Austin, Tx