Advice needed on a new RIB for tourism in Brazil

[Robbie D]

I would like to begin by saying how much I enjoy your forum. Wisdom combined with wit make for an enjoyable learning experience. I am starting an ecotourism business just outside of Rio de Janeiro and would greatly appreciate any help or advice offered. I am more or less forced to go with a Brazilian manufacturer of RIBs because of lack of vendor support for imports. They seem to make a decent quality boat on the surface (no pun intended), and they offer a seating configuration unlike any I've seen from another maker. If anyone is interested in offering some feedback, they have an English version website since they're starting to export to the U.S. The model I am most interested in is the SR-760, 22 person diesel sterndrive version, unless someone has a compelling arguement to go with petrol sterndrive or twin OB's (not intended to start another forum sh**storm).

Their main site is:
www.flexboat.com.br

and the page that links page to all the versions is:
http://www.americanflexboat.com/pro...sr760models.htm

They will put in a Volvo or a Yanmar, but service here is better and more widespread for Mercury. If I can sell enough blood, I'd probably opt for the cummins mercruiser 4.2L D-Tronic 250hp (225@prop) with a Bravo 3 leg, and possibly an auxilliary outboard (will always be close to shore with other boats nearby). Since I'll be hauling around an average of 3000 lbs. worth of tourists 3 or 4 times a day, my main concerns are low-end torque for faster planing under load and fuel economy. Average cruising speed will be about 28 mph with not much need for higher speeds or WOT (unless I'm trying to impress a string-bikini-wearing Brazilian nubile). Also, diesel prices are roughly 65% of petrol prices, and petrol quality can be circumspect down here.
The price of this configuration, fully rigged without the motor, is 31,000 USD. The list price for the 4.2 D-Tronic here is 36,000 USD, so I'll be trying to import a new one or find a good quality used unit. They'll install any motor I send to them with no additional labor charges.

The basic route will include calm water, open ocean, maneuvering through sea caves and rock formations, and whale/dolphin/turtle watching, depending on the season. And a few beach stops for swimming.

Any comments or suggestions, negative or positive, will be greatly appreciated. I hope to be a regular in these forums and one day hope to understand half as much as most of you know about Ribbing.

Thanks in advance, RD

Free rides for any and all who can make it down here!

[Manos]

Am I to understand correctly that this is a 25 ft boat (7.6 mtrs) and it takes 22 people seating plus the skipper? What is the beam?

[simmons0]

Have a look at the website Manos. They really do fit 22 seats into a 7.6m rib.
Only with outboards though, it's be more like 16 wiht an inboard.

These guys will even make a flybridge 7.6m rib!

[Manos]

I looked this is why I'm asking. It seems impossible to me unless the beam is near to 3.5-4 mtrs

[tim griffin]

i,m with Manos it does seem alot of people on a rib that size, must pack them in like sardines,even though the beam is 3.3 metres
tim
www.griffmarineservices.co.uk

[Rogue Wave]

Originally Posted by tim griffin

i,m with Manos it does seem alot of people on a rib that size, must pack them in like sardines,even though the beam is 3.3 metres
tim
www.griffmarineservices.co.uk

If you look at the CE plate on the back of your rib you will find it's rated for al lot more people than one would want to put on it. I think they do it on weight. My Avon 8.4 is rate dfor 24 and my 4.7 was rated for 7 ( which beggars belief!)

Robbie I do have a concern about the number of people you are carrying , the performance of the engine is going to be compromised somewhat so you might hve to keep the hammer down to maintain an average speed. This might compromise your wave riding technique.

Also the most charter guests I have had on a rib was 12 and that was very difficult to keep track of how they were doing in terms of safety and comfort if you have more than that on board you are definitely going to need a crew member to help with this task.

The rear driving position is a must for that many people as is diesel power for operating economy but can you get a bigger one as I thing it's going to be a bit chuggy.

another thing I would want to check out is what the ride is like for the front apssengers.

All in all it looks like a wonderful venture and I wish you the best of luck

[Manos]

Originally Posted by Rogue Wave

If you look at the CE plate on the back of your rib you will find it's rated for al lot more people than one would want to put on it.

It depends if is Cat C or Cat B or Cat A.

For 5 mtr RIB Cat C the (Watercraft 5mtr) the max persons permited onboard are 10 for a Cat B and Cat A the max persons permited on board are 6. I know I've got one

[Jelly]

When I was down in Rio we got the local Volvo guy to rebuild the Ships FRC.
Crew said it was fine always started and went out - sometimes came back!!!!!!!!!!

That was a Huricane with a volvo leg etc. He was able to rebuild it about 2-3 days from being called in. Sorry no name but he was the local guy.
Hope it helps
James

[simmons0]

[Manos]

Still don't think so, seating looks very crampt to me, no grab rails to hold from for the front passengers, I don't think that there are any grab rails for any actually, but if they run it good luck to them.
Where I operate my RIBs this boat as is, would never got a commercial licence.

[tim griffin]

Originally Posted by Rogue Wave

If you look at the CE plate on the back of your rib you will find it's rated for al lot more people than one would want to put on it. I think they do it on weight. My Avon 8.4 is rate dfor 24 and my 4.7 was rated for 7 ( which beggars belief!)

Hi rogue
not the dreaded RCD CE PLATE again
i know what you are saying ref this it just seems a awful lot of people for that size rib, even on the 7.5 it would be a squash how ever if the company can build them like that ,who am i to argue different countries different regulations i think its a great oportunity for this guy and i agree with you in regards to performance with this amount of people and the safety aspect
but that will be down to engine selection and safety policy but great venture
and good luck
tim
www.griffmarineservices.co.uk

[Robbie D]

Thanks for all the replies. I was out doing research for the project and I'm sorry I didn't take part in the replies. As for the seating and safety issue, this configuration has been around for a while and tested under some adverse conditions.... see photo.
[IMG]
Judging by the replies I need more hp, maybe 285-300? Reliability is my most important consideration, since down time = no income. Ease of maintenance and fuel economy come next. Does anyone have an opinion on the most reliable sterndrive motor/leg combination for this type of application? Mercruiser/Volvo/Yanmar and which leg? I would even go with petrol I/O or outboard if it was a more reliable option. Low-end torque is more important than top speed because of the weight.
Thanks for sharing your experience!
Rob

[Manos]

WOW the boat looks huge Robbie
Am I to assume that you have 3 seats per row rather than 4?
Feel pity for the guys sitting in the bow section though
By the way did you say that you operate it in sea or fresh water areas?
Does it have a CE certificate, in what category is clacified to be and by which agency?

[Robbie D]

Originally Posted by Manos

WOW the boat looks huge Robbie
Am I to assume that you have 3 seats per row rather than 4?
Feel pity for the guys sitting in the bow section though
By the way did you say that you operate it in sea or fresh water areas?
Does it have a CE certificate, in what category is clacified to be and by which agency?

It's hard to believe it's under 8m, isn't it? The Ribs in the pictures have 4 seats across and hold 27 passengers, but I would go for 3 across for room to move around on deck. Mine will hold 22. It will be used strictly in salt water. The agency down here in Brazil who governs the ratings is the Port Captain, and they usually go along with whatever the manufacturer says is the capacity. The category they's give this (translation) is for a passenger boat operating within 10 kilometers of the coastline. Definitely a lot less regulation than what you have there.
The more I'm reading about problems with stern leg problems on bigger diesels the more I like the outboard option. What do you think?
Here's another configuration for the inboard model... holds 22 and the crew sits on top of the engine hatch. I'd probably keep the number of passengers down to about 16 so nobody sits on the bow for the open ocean part of the ride.

[Manos]

Outboards would have been my choice rather than inboards.
The boat looks huge and 3 pax per row sounds more reasonable rather than 4. However if the boat is not CE marked and category certified is illegal for operating in European waters (unfotunately).
Enjoy it in Brazil is a great country from what I can remember the little time I've been there sometime in the past

[Robbie D]

Hey Manos, I think our posts crossed paths. I'd be really curious to find out why you'd opt for outboards?
My thinking, correct me if I'm off, is that for a commercial operator, any problems with an inboard/outboard system would keep you out of the water for days if not weeks. An outboard can be swapped out with a borrowed or spare unit in less than a day!
Petrol costs about 40p per gallon more than diesel here, however.

[Manos]

As my engineer said sometime ago outboards have less moving parts (apparently) than inboards, hence less chances for things to go wrong. Most of my friends that have inboards have some kind of a problem (big or small) from time to time.
If you have a problem with an outboard and you need to change it, as you say, out she goes and put another one on in about 30 mins. With an inboard it may take a day
I like outboards and 2-strokes my self, proven and tested and the engines that are made today NEVER go wrong (at least 99% of the time )

[Searider]

Robbie,

Do the suppliers have a diesel engined demo boat?
If you could ballast this up to a full loaded displacement then you could decide for sure what engine is required. It's going to be a heavy boat with 16+ people on board.

My concern would be the engine bogging down when trying to get onto the plane. Perhaps a Volvo KAD43 / 44 / 300 series engine might suit as these have superchargers for low end torque.

Another option would be to consider a waterjet - this would allow the engine to spin up to maximum speed irrespective of load. However, this option is likely to push the cost up and probably take up more space in the boat.

There are several users on here with bigish ribs with single diesels - perhaps they could chip in?

Duncan

[Robbie D]

Originally Posted by Manos

As my engineer said sometime ago outboards have less moving parts (apparently) than inboards, hence less chances for things to go wrong. Most of my friends that have inboards have some kind of a problem (big or small) from time to time.
If you have a problem with an outboard and you need to change it, as you say, out she goes and put another one on in about 30 mins. With an inboard it may take a day
I like outboards and 2-strokes my self, proven and tested and the engines that are made today NEVER go wrong (at least 99% of the time )

Hmmmmmm.... tempting! Now for the dreaded question. Optimax or Honda four stroke? Would a single 225 do the job or a pair of 150's?

[Robbie D]

Originally Posted by Searider

Robbie,

Do the suppliers have a diesel engined demo boat?
If you could ballast this up to a full loaded displacement then you could decide for sure what engine is required. It's going to be a heavy boat with 16+ people on board.

My concern would be the engine bogging down when trying to get onto the plane. Perhaps a Volvo KAD43 / 44 / 300 series engine might suit as these have superchargers for low end torque.

Another option would be to consider a waterjet - this would allow the engine to spin up to maximum speed irrespective of load. However, this option is likely to push the cost up and probably take up more space in the boat.

There are several users on here with bigish ribs with single diesels - perhaps they could chip in?

Duncan

Searider,
I think I'll get a chance to test one this weekend if I'm lucky. They've put a couple of Merc 220hp diesels in with Bravo 3's, but those were set up for half the passengers. I think I'll try to get in touch with some owners.
As for waterjet, no one here know what one is let alone be able to work on one! The simpler the better down here.