AB Inflatables

[tonyraymond]

Hi, I am interested in buying a AB Alumina 11 ALX. It is spec'd to have a max 20 HP engine. The dealers in the US won't sell it with a bigger motor for fear of liability if someone hurts themselves.

I was wondering if any of you have experience or knowledge of how the boat will perform. I want to use it for a dinghy to go to and from the big boat mostly. But would also like to pull the kids on a tube and I'm not sure 20 HP will produce enough thrust. I know I can "prop it up" a bit to get more speed but at the sacrifice of low end power. Any thoughts would be greatly appreciated.
Thanks

[Nos4r2]

Welcome to Ribnet

You'd be mad to over-engine it in these litigious times. I suspect you'll find your insurance wouldn't cover you for it if there was an accident.

20hp probably won't be enough.

[tonyraymond]

You are right about the liability aspect.

I would really like to get a speed curve for 20 HP.
The US distributor told me that AB doesn't provide it as they don't sell engines. Which is a way of avoiding the question. Using crouch's law the boat designer can at least draw a theoretical boat speed curve. Does anyone have a guess on what Hull factor to apply to this RIB.

Thanks

[jyasaki]

Originally Posted by Nos4r2

20hp probably won't be enough.

For an 11 ft RIB? Maybe not for a go-fast RIB like a lot of you UK guys seem to go for; for a get-around, not in a hurry type boat, I'd think it would be fine (though we probably are talking light loads and small numbers of passengers...)

A buddy of mine runs a 13' (I think) AB RIB in fiberglass, running a 40hp 4-stroke. Does OK, even loaded up with a couple of divers and gear.

jky

[Nos4r2]

Originally Posted by jyasaki

For an 11 ft RIB?

No, for pulling tubes with an 11 ft rib.

[jyasaki]

Ah. That's probably true.

jky

[office888]

Why not get a bigger fiberglass RIB? Like a Zodiac Pro Classic 420 or Bayrunner?