New boat?

tue · 17 November 2003, 18:04

I am thinking of selling my 6.5m Ribtec early next year with the idea to get somthing a little more conservative

. The only problem is I don't know which RIB to get. I am fairly certain on a 1.7tdi engine and I don't want to go much bigger than 7m.

I have looked at Humbers 6.3m Ocean pro which has good performance figures: with 8/10 divers on board 35 Knots (its main use will be diving), light load 40 Knots each with 23" props. And burning apparently £2 an hour diesel!!

Prosport appear to be good but not as good on the performance (if Humbers figures can be believed).

I don't want to fly around the place like a nutter but 30-35 Knots with divers on board would be preffered. Any other ideas on RIBs that would do the trick. I have a budget of around k20. I may also consider a boat with an Opti

.

Also does having the engine box in the boat take up alot of space? or can I use the cover for bottle storage?

simmons0 · 17 November 2003, 18:16

How about the boat that i have just put the pic of on the Prosport thread.

tue · 17 November 2003, 18:17

9m is a bit large to tow around the place

John Kennett · 17 November 2003, 19:00

I don't believe those figures quoted for the Humber. I reckon that the top speed is more likely to be no more than 35 knots, and much less with ten divers on board!

Are you happy with your RIB apart from the fuel bill? Have you thought about just re-engining itwith something a bit less thirsty? A 150 Optimax would give you good performance and use a whole load less petrol than your old 200.

You'd still be spending a lot more on fuel than with a diesel, but it's probably worth working out the sums . . .

John

Ian · 17 November 2003, 19:09

tue, have a word with Pro Sport and try to get like for like figures for comparison. Are the Humber figures in lab conditions or real useage conditions? For marketing purposes they'll have selected the best sea state and optimum loading for the tests, as I'm sure they all do.

tue · 17 November 2003, 20:46

Quote:

Originally posted by John Kennett

Are you happy with your RIB apart from the fuel bill? Have you thought about just re-engining it with something a bit less thirsty? A 150 Optimax would give you good performance and use a whole load less petrol than your old 200.

You'd still be spending a lot more on fuel than with a diesel, but it's probably worth working out the sums . . .

John

I have considered it. We have a 150 Ficht at work but I don't like them much and I'd need to sell my 200 first to get get some cash in for the Opti.

Know anyone who wants a 1999 200hp Mariner with about 50hrs on it

tue · 17 November 2003, 20:49

Quote:

Originally posted by Ian
Are the Humber figures in lab conditions or real useage conditions? For marketing purposes they'll have selected the best sea state and optimum loading for the tests, as I'm sure they all do.

Apparently they are done using owners reports in conjuction with Mercruiser.

So they looked at the owners reports, looked at the manufacturers reports and made up some figures completly different that looked good

Ian · 17 November 2003, 21:00

thought so

Jason Norman · 18 November 2003, 05:52

We are getting 35 kts with full fuel and 3 persons on board thats with a 23 pitch prop pulling 4200rpm,

we could probably swing a 25 pitch to increase the top end but I have to agree 40 kts is a long way off???

Drop me an email if you want some more info also i will send you some pics

Andre · 18 November 2003, 11:04

Tue

Welcome to the Mercruiser 1.7L TDI fan club

I see that this engine is begining to be very popular and so it should.

We have a new member Tero Johansson from Finland and his profile says he has a Revenger 7 mtr with the Mercruiser 1.7 L TDI

Tero, welcome to the Forum I hope you enjoy it.
What can you tell us of the performance of your Revenger with this engine ie, top speed, fuel consumption, ect

Andre

PS. Jason's latest figures are now more realistic

tue · 18 November 2003, 17:50

Anybody here tried the Humber Destroyer 7m. Is it likely to be a bit unstable due to its long thin sizing? I was thinking of maybe putting a 150 Opti on the back. Any comments?

tue · 18 November 2003, 17:53

Quote:

Originally posted by Andre

Tero, welcome to the Forum I hope you enjoy it.
What can you tell us of the performance of your Revenger with this engine ie, top speed, fuel consumption, ect

It would be nice to know the figures for a 7m boat.

Also what sort of speed do you rekon you could get on a 6.5m 1.7tdi with 6-8 divers on board?

Alex Brown · 18 November 2003, 18:05

I have a Humber Destroyer 6m with a 140 on the back if that's of any help?

It's very stable, and grips the water like glue at speed

-Alex

tue · 18 November 2003, 18:13

Alex, what sort of figures are you getting on your Humber, fuel consumption, speed etc?

Andre · 18 November 2003, 18:19

Quote:

Originally posted by tue
It would be nice to know the figures for a 7m boat.

Also what sort of speed do you rekon you could get on a 6.5m 1.7tdi with 6-8 divers on board?

Tue

Perhaps we will hear soon from Tero cos his reply will be rather interesting.
I do not believe you will get more then 30 knots out of a 6.5 mtr rib (1.7 TDI) with 6/8 divers and equipment and this will mean testing it with the 23 and 25 inch prop.

I am keen to test these props as I have only used the 21" LASER II but will wait till the spring when my new rib arrives

Andre

jwalker · 18 November 2003, 18:29

Yep, had a 6.5mtr for 7 years. It was a good boat. Used a 150hp for 3 of those years but it was much more fun with the 200hp. It is quite a norrow boat, so internal space is a bit limited but stability is not compromised by this. Sold it earlier this year to group of divers. They are delighted with it. In this pic the boat looks a bit low in the water. It had been raining for 3 days prior and the hull was full to the top of the transom cutout.

jwalker · 18 November 2003, 18:41

I have a wee program which was written specifically for this boat.

@ 4200rpm, 2:1 gear ratio, 23" prop and 2 people on board = 35.6mph.

Ask me another..........

Alex Brown · 18 November 2003, 19:16

It maxes out around the 43knot mark in a no wind no tide situation, which is approx 50mph. Before Wavehumper says, yes, the 4-stroke is slower than the 2-stroke opti, but not by much I don't think.

On a good day, I get around 1.6miles to the litre of fuel, a bad day is about 1.2miles to the litre with 8 people on board, and giving lots of throttle. I seem a average around 1.4litres to the mile though.

Being quite small, there is quite a bit of twist from the prop at higher revs, although this isn't obvious with the engine trimmed right out, when trimmed in in chop, you can feel the boat more keen to lean to port than normal, which is fine, just so long as you're ready for it

Other than that, I'm very happy with it - any attempted takeoffs are always ended with a very soft landing with very little 'crash', which worked out great last weekend when we were playing around in the swell at St Annes.

-Alex

Tero Johansson · 19 November 2003, 08:25

Quote:

Originally posted by tue
It would be nice to know the figures for a 7m boat.

Also what sort of speed do you rekon you could get on a 6.5m 1.7tdi with 6-8 divers on board?

Terve,
I have got this set up since last summer working as all-around-boat. Some of you guys were already writing that top speed is not too much. Well, that's correct. With full tanks (ca.230l) 3pax and with 3900rpm it does something 25-28kts.
What I'm very happy about is fuel cons. It takes with 80% power like 16ltrs / hour. It make familyman very

.
The onlything that could be better with this configuration is powerpack weight. It's power/weight-ratio is not the best but like I wrote above fuelcons. is good and important to me.

BTW, do you guys know if am I only finn in here?
Brg///Tero

Jari Hjerppe · 19 November 2003, 18:58

I think here are now four of us (Finns).

Jari