Don't really need a Rib?

[Tim Good]

I hear that a lot of cruising liveaboards benefit from ribs or so it seems. We have a really good air deck Avon inflatable but it still doesn't go very fast with our 4hp 4-stroke.

Would I see I huge difference with a rigid bottom inflatable? Is it worth is bothering with?

 

[jimbaerselman]

I hear that a lot of cruising liveaboards benefit from ribs or so it seems. We have a really good air deck Avon inflatable but it still doesn't go very fast with our 4hp 4-stroke.

Would I see I huge difference with a rigid bottom inflatable? Is it worth is bothering with?

Weight, and deck stowage.

I was able to lift my 4HP off, and stow it astern inside the pushpit. Then I bounced the aerodeck on board single handed just forward of the shrouds - to stow inverted between mast and forestay.

I could plane it one-up with shopping on board!

 

[Tranona]

Downsides with RIBs is weight, storage, and of course cost. which you choose depends on what you expect from the tender. If it is just short journeys to and from shore with low payloads at low speed then what you have is fine. If however you are looking at longer trips with heavier payloads and planing speeds - as is common in anchorages in the Caribbean then you will see why larger RIBs with big motors are common. Then you need to be able to stow them either on davits or have a foredeck big enough to take it - plus a good means of hoisting it on deck.

There are some new lightweight smaller RIBs, some folding which are a sort of halfway house, but inevitably expensive, particularly if you then want a more powerful engine to make use of the greater performance potential.

 

[TQA]

There is a reason why most long termers have ribs [ at least in the Caribbean ] They are drier faster and more stable.

Just off to launch mine.

 

[GrahamM376]

Would I see I huge difference with a rigid bottom inflatable? Is it worth is bothering with?

Just for speed, not worth changing as your engine is small. It would be more cost effective to bin the small 4 stroke and find a larger second-hand 2 stroke. Our 2.9m inflatable planes easily at around 17 kts 2 up + shopping, with 2 stroke 9.8hp engine.

 

[charles_reed]

Having moved from an inflatable keel dinghy to a RIB, I'm afraid you have to make a choice based on your needs. Neither is an overall winner.

A RIB is far more stable, has considerably greater carrying capacity and is far drier in a seaway. A polyester RIB appears to have the same life-expectation as a Hypalon inflatable V and is more prevalent and cheaper.
Being far heavier you do need a larger motor to exploit its greater speed potential - but with a 3.3 2 stroke the RIB is as generally as fast and uses less fuel - I too used to be able to plane, 1 up on my inflatable V, but that had more to do with noise, spray and excitement than with an outright increase in average speeds.
The replacement RIB is a 2.4 nominal length, but occupies the same length of foredeck as the 2.6m inflatable V.
Due to the greater depth of hull, getting in and out of the RIB, is considerably less easy than the inflatable, but then falling in is also far more difficult. Boarding from the water is physically more strenuous with RIB, but less likely to result in capsize failures.
Not having davits makes the RIB far more inconvenient than the deep-V inflatable for carrying, but it does seem to tow far better and at 7.5kts (impossible with the deep V inflatable).
One major disadvantage - because the only place to stow the dinghy is on the foredeck - I can't use solent or working jib with the dinghy aboard, because the hull covers the sheet-blocks. So in heavy windward work I'm constrained to using the 110% genoa which increases overall tacking angle by 10 degrees (towing the RIB is even more of a handicap).
My impression is that RIBs are more favoured by long-term liveaboards.

And, if you can afford the weight of a 15hp OB, they're a LOT faster.

 

[affinite]

Just for speed, not worth changing as your engine is small. It would be more cost effective to bin the small 4 stroke and find a larger second-hand 2 stroke. Our 2.9m inflatable planes easily at around 17 kts 2 up + shopping, with 2 stroke 9.8hp engine.

I bet I'm not the only one on the lookout for a good second hand Tohatsu 9.8 2stroke

 

[dunedin]

Do the users of RIBs plus large outboards only tend to land at dinghy docks (and/or in non tidal waters) ?

Most of the time we use the dinghy we tend to be landing on the shoreline - a beach or harder ground. Need to be able to lift the dinghy and o/b a consirable way - either up the beach if on rising tide, or back down if tide has gone down since arrived. Quite a struggle with a flat floored 2.6m dinghy and 2.5hp two stroke. Expect would be a nightmare with a bigger RIB

 

[Hadenough]

Sold my Tohatsu 9.8 two stroke last year. Fantastically powerful and light but horrendous fuel consumption. My new 4stroke doesn't have the oomph but still gets me on the plane in a 2.8 ally RIB and consumes 75%! less fuel than the two stroke.

 

[tcm]

Your liveaboard life will be less enjoyable in a smaller/weedier/wetter/slower rather than larger/sturdier/comfier/faster dinghy. Perhaps think of it like this : your boat is your house and your dink is your car. If it's so slow that you plan dinghy trips carefully (instead of just razzing around) then it's like having a bicycle instead of a car - quite nice but usually hard work and/or just about sufferable ... and sometimes just a pain. Make a planing comfy dink a priority BUT... note that the super-sun-resistant AB and Carib dink (rib) brands are most easily and cheaply bought in the caribbean, so perhaps wait till you get there (st martin probably cheapest..) as are lightweight 2-strokes 10hp should easily plane 2 people, 15hp the norm for even mucky hull or loaded dink, 25hp and up for the speed freaks and power crazed loons. forget the speed limits printed on the rib that's just for manufacturer's liability when actually a 2m rib will really crack along with 25hp on the back yeahah woohoo and then set the tilt thing so it'll kick up on it's own and wham it straight up th beach wooomph haha..... er dang!- another post that started really sensibly and went of the rails...

 

[geem]

Sold my Tohatsu 9.8 two stroke last year. Fantastically powerful and light but horrendous fuel consumption. My new 4stroke doesn't have the oomph but still gets me on the plane in a 2.8 ally RIB and consumes 75%! less fuel than the two stroke.

interesting about fuel consumption. We have had the same engine for 11 years and the fuel consumption is incredibly fugal. On a three week holiday in Scilly isles our friends used lots more fuel with their tiny 2.5 hp and 3.5 hp engines in three weeks than we used with our Caribe Rib and 9.8hp. We went further, faster and drier than them as well.

 

[GrahamM376]

interesting about fuel consumption. We have had the same engine for 11 years and the fuel consumption is incredibly fugal. On a three week holiday in Scilly isles our friends used lots more fuel with their tiny 2.5 hp and 3.5 hp engines in three weeks than we used with our Caribe Rib and 9.8hp. We went further, faster and drier than them as well.

It's a great source of amusement watching inflatables with small engines running out of fuel after spending more time just stemming a good tide than going anywhere.

 

[Strolls]

On a three week holiday in Scilly isles our friends used lots more fuel with their tiny 2.5 hp and 3.5 hp engines in three weeks than we used with our Caribe Rib and 9.8hp.

So is your engine 2-stroke or 4-stroke, please?

And your friends' smaller engines?

 

[TQA]

I find my Tohatsu 18 hp 2 st to be very economical. I guess inpart because once we are up and planing I am on less than 1/2 throttle.

Full time liveaboard with some long runs and I use about a gallon a week.

 

[GrahamM376]

I find my Tohatsu 18 hp 2 st to be very economical. I guess inpart because once we are up and planing I am on less than 1/2 throttle..............

And a hell of a lot drier than those not planing whenever it's choppy.

 

[Boo2]

I bet I'm not the only one on the lookout for a good second hand Tohatsu 9.8 2stroke

Mainbrace say they still have the T9.8 2-st, see here.

Boo2

 

[geem]

So is your engine 2-stroke or 4-stroke, please?

And your friends' smaller engines?

Two stroke 9.8hp. Friends run All sorts of 2.5/3.5/4 hp2 strokes. Nobody likes 4 strokes for their weight. Here in Caribbean you can buy both four and two stroke but nobody in their right mind buys the four strokes

 

[tcm]

Two stroke 9.8hp. Friends run All sorts of 2.5/3.5/4 hp2 strokes. Nobody likes 4 strokes for their weight. Here in Caribbean you can buy both four and two stroke but nobody in their right mind buys the four strokes

Agreed. And the yamahas are much preferred to Tohatsus which sound like a bag of nails.

 

[rickym]

True but the 10HP yamaha is heavier than the Tohatsu, yer pays yer money.....

 

[geem]

Agreed. And the yamahas are much preferred to Tohatsus which sound like a bag of nails.

All the charter companies us Tohatsu so Yam are getting something wrong somewhere.
We chose Tohatsu over Yamaha as we had great experience with our first 9.8hp before it was stolen. We had that engine for 11 trouble free years and it never sounded like a bag of nails. The new one is just as smooth as my pals brand new Yam.
The Tohatsu is lighter than the same power Yam. That's important to us.
If we wanted a 15hp we would go for Yam Enduro but we don't want one so it won't happen. The weight of that engine is 9kg more than the Tohatsu 9.8. The difference between man handling and needing a crane.