Jet Rib

[cpleigh]

Im looking for a rib to to use for fishing skiing picnics etc.

The rib will be moored in an estuary and I am keen to be able to use it in a wide tidal range as possible and therefore shallow water before the open sea.

I have seen a few references to inboard jet ribs of which most are commercial or tenders. I understand there is a 30% reduction in power using a jet drive but inspite of this why dont more manufacturers produce 5 to 7 meter jet ribs ? Is there a reason ?

Has anybody had good/bad experiences with this sort of configuration and what make of rib/engine are they.

[Andre]

Originally Posted by cpleigh

Im looking for a rib to to use for fishing skiing picnics etc.

The rib will be moored in an estuary and I am keen to be able to use it in a wide tidal range as possible and therefore shallow water before the open sea.

I have seen a few references to inboard jet ribs of which most are commercial or tenders. I understand there is a 30% reduction in power using a jet drive but inspite of this why dont more manufacturers produce 5 to 7 meter jet ribs ? Is there a reason ?

Has anybody had good/bad experiences with this sort of configuration and what make of rib/engine are they.

We fitted a Mercruiser 1.7 DTI and jet drive on our Parker 630, expensive package and max speed only 26 knots. - hence not much interest from private buyers
see link: http://www.parkerribs.com/?page=news_read&id=8

we showed this rib at Ribex 2006.

[codprawn]

Which estuary is it as a matter of interest?

[Poly]

Originally Posted by cpleigh

Im looking for a rib to to use for fishing skiing picnics etc.

The rib will be moored in an estuary and I am keen to be able to use it in a wide tidal range as possible and therefore shallow water before the open sea.

I have seen a few references to inboard jet ribs of which most are commercial or tenders. I understand there is a 30% reduction in power using a jet drive but inspite of this why dont more manufacturers produce 5 to 7 meter jet ribs ? Is there a reason ?

Has anybody had good/bad experiences with this sort of configuration and what make of rib/engine are they.

perhaps pm cookie - i think he has/had one of their new 6m(ish) boats with a jet in it.

I guess most people don't have major concerns re shallow water or prop safety so the compromise in cost/performance is not necessarily worthwhile.

[cpleigh]

Originally Posted by Andre

We fitted a Mercruiser 1.7 DTI and jet drive on our Parker 630, expensive package and max speed only 26 knots. - hence not much interest from private buyers
see link: http://www.parkerribs.com/?page=news_read&id=8

we showed this rib at Ribex 2006.

Thanks,

I guess with the jet drive power issue a larger engine would be needed to give acceptable power.

[cpleigh]

Originally Posted by codprawn

Which estuary is it as a matter of interest?

Its the estuary on the east of Holy Island adjacent to Anglesey.

[Juspalm]

Hi, I've been running a jet rib for eight years and it's great. It's a 5.8 metre with a Yanmar 4lh (170hp) on a Castoldi 05 jet. I get a mile a litre and 30 knots max 24 cruise. I also work with 2 jet work boats one twin engine running perkins on hamiltons which is amazing and you can put it anywhere including sideways etc etc. Mine will be forsale soon
jus

[pressman]

We have just delivered a 6m with inboard Yanmar and Hamilton jet. Cheers Mr Tilley the toobs looked great

[cpleigh]

Originally Posted by pressman

We have just delivered a 6m with inboard Yanmar and Hamilton jet. Cheers Mr Tilley the toobs looked great

D'you have any photos/details. Maybe a link to a website.

Ta

[cpleigh]

Originally Posted by cpleigh

Im looking for a rib to to use for fishing skiing picnics etc.

The rib will be moored in an estuary and I am keen to be able to use it in a wide tidal range as possible and therefore shallow water before the open sea.

I have seen a few references to inboard jet ribs of which most are commercial or tenders. I understand there is a 30% reduction in power using a jet drive but inspite of this why dont more manufacturers produce 5 to 7 meter jet ribs ? Is there a reason ?

Has anybody had good/bad experiences with this sort of configuration and what make of rib/engine are they.

I think Ive found my ideal boat configuration

www.zodiacmilpro.com/product/sbyt/info/558DJ.pdf

I dont need the professional specification and am not boothered about it being zodiac. 4 Saddle type seats, about 5.5 meters with a jet drive.

Anybody know a source or make model

Please advise

[Cookee]

Originally Posted by Polwart

perhaps pm cookie - i think he has/had one of their new 6m(ish) boats with a jet in it.

I guess most people don't have major concerns re shallow water or prop safety so the compromise in cost/performance is not necessarily worthwhile.

Hi - We have a boat in stock with the same unit as the Parker (Mercruiser 120 diesel waterjet) in a 6 metre hull - we have had 36 mph out of ours and I reckon we average about 12 Litres per hour although the official figures at full speed reckon about 25 litres and hour to be correct. At the moment the boat has a wakeboarding frame on it, a bench seat and two front seats with a temporary console. Email me for more details and photos if you want to know more! cookee@bananasharkracing.com

The boat is so much fun to drive, especially doing crash stop 180's at full throttle! We can fit any seating and console arrangement to suit the projected use of the boat by the way!

[yorfuoj]

several years ago I made a prototype to match a particular request.

The boat was a Tomcat 5metre catamaran.
I installed a Mercury 60HP outboard, fitted with a jet leg instead of the standard prop leg.
Due to the fact that the speed was lifting the hull, I had to make some special GRP extension, but it worked well.

The speed was approximately 23 kn, normal when you know 30% of HP is lost.

The result would have been much better with a twin engine indeed, because in this case the waterflow entering the turbine would not be affected by the hull heigth, turns, etc... wich make it behave like cavitation.

This is a cheap and very efficient solution : buy a pair of standard outboard engines, and a pair of waterjet extension.
The extensions are very cheap - approx 1500 to 2000$ - easy to install, and they exist for most engines up to 200HP and up. Much less than waterjets packages, and you have both possibilities for the same price, waterjet or prop either.

I will fit my next rib (Tomcat 570 with 2x50HP, or 610 with 2x70) with that.

[Tiffy]

Avon make a Jet Rib about 5.4 meters. Modern Jets are very efficient .
Achilles heels in shallow water they suck up shingle and other muck from
the bottom. We once built one in a Avon 4.5 m with a rotax engine and
UA jet> A outboard with hydraulic trim will go in shallower water than a
jet. Barrus make a outboard water jet .We now have a 9.5 meter Ocean
Dynamic with 400hP Iveco Diesel and Hamilton Water Jet Rescue Rib
Hope this helps. "Tiffy Venturers " SAR