Jetpack?

[jwalker]

Originally Posted by Polwart

Each to their own I suppose - ...

Yeh, I guess so. I had wondered about a couple of 200hp Jetpacks on the back of a rib around the 8-9mtr length. The Jetpack is a bit less that 1.5mtrs so you'd end up with a pretty big boat and lots of internal space. A couple of big trimtabs would give you trim and list adjustment. The engines are well tried units and, I'd guess, spares would not be an issue. Not that you've want to break them. It could be a good solution. They are a bit on the expensive side though. I believe 2 of these would set you back about £34k. Frightening.

[houser]

That's pretty my take on it exactly.
I want diesel, jet and space onboard with as small a RIB as possible and that is where the USP is for me.
If I can go fast-ish too then that will not hurt...;-)
Wonder how one of these would fit on the back of something like a Redbay Expedition? WOuld give you the aft deck back.
Ah well..

best
jtm

Originally Posted by jwalker

Yeh, I guess so. I had wondered about a couple of 200hp Jetpacks on the back of a rib around the 8-9mtr length. The Jetpack is a bit less that 1.5mtrs so you'd end up with a pretty big boat and lots of internal space.

[Matt]

Mmm. With a "small a rib as possible" I'd be concerned about all that weight right at the back - it's gonna be heavier than the equivalent outboard, hanging further off the back. Does the transom require additional reinforcement beyond that of an O/B boat?

[Pete7]

Originally Posted by Matt

Mmm. With a "small a rib as possible" I'd be concerned about all that weight right at the back - it's gonna be heavier than the equivalent outboard, hanging further off the back. Does the transom require additional reinforcement beyond that of an O/B boat?

I was wondering that too. If a 6m rib is fitted with a jetpack then its going to be a 7m rib. Why not just buy a 7m rib to start with, at least it would be a known quantity. I seem to remember a Tremlett rib prototype that had an engine change and didn't perform.

http://rib.net/forum/showthread.php?...t=tremlett+rib

Pete

[jwalker]

Originally Posted by Matt

..I'd be concerned about all that weight right at the back - it's gonna be heavier than the equivalent outboard, hanging further off the back.

Well, initially you might think so but the units have their own buoyancy so when floating they will be supporting much of their own weight. When airborne, I guess it's going to depend on how that occurs but under power it's the jet unit that is driving the boat out of the water so the two of them will be flying together. The landings could be good or bad depending on the attitude of the boat. But, as I said earlier, if wave jumping isn't your thing then I feel they could be made to work satisfactorily.

The hardest landings I'd experienced are when in clapotic seas and big hole appears under the boat. On a bad landing, that could do for them but I guess that applies to an inboard installation too. I know folk who've cracked an engine block in that situation.

It's worth discussing though cos it helps yer brain assess.

[Cookee]

And what about that great lump hanging off the back when it's on the trailer?

[jwalker]

Originally Posted by Cookee

And what about that great lump hanging off the back when it's on the trailer?

Where there's a will there's a way, I suppose.