Very Small RIBs

[GandyGoose]

Hi,

First post here, please be gentle. We're thinking of getting a small RIB, around 3m, to use as a tender to our sailing boat on its swinging mooring, and for pottering around. It needs to be able to carry four people on rare occasions, two people plus luggage more often. I'd prefer Cat C, since there can be a bit of chop kicked in some places, and powerboat wash as well.

Currently we're using a 10ft fibreglass dinghy with a Merc 2.2, but that's not ideal for a few reasons. Its a bit tippy and certainly doesn't feel secure for passengers in any sort of chop. That same tippiness makes it less safe getting between boat and tender than I'd like. Then the fact that its hard means we need to mess around with fenders etc when its alongside.

Looking at some boats in the dealer, I liked the look of the Zodiac Zoom 310. The solid hull seems sensible.

Really I was wondering about the pros and cons of a RIB vs an inflatable floor boat at these sizes, and whether there were other comparable or better or cheaper models that I should look at.

I haven't even thought about motors yet. Maybe try the 2.2 and see how much more oomph it needs. The 2.2 pushes our hard dinghy fast enough to throw up a fearsome wake.

Thanks in advance for any comments,

Tony S

[codprawn]

If the boat will never be stored away go for the hard bottom. If you want to chuck it in the cabin or the back of the car go for a softie.

I have a Quicksilver 3.1m which is great - has carried 3 adults and 2 kids at about 20mph with a suzuki 15hp 4 stroke.

A 2.2hp is very small - I wouldn't go for less than a 7.5. Never kn ow when you need the extra grunt.

http://rib.net/forum/showthread.php?...uicksilver+310

I would go for a 2 stroke - much lighter.

[Poly]

I think cod is right 2.2 HP may struggle a bit with a boat that size if the chop is bad enough to genuinely justify a cat c boat (oh oh - thats probably just started a third thread debating the value of the RCD ).

I don't think you will need to go as big a 7.5 HP though. Whilst it would be nice to think you could get the rib on the plane if you wished to do so lightly loaded - what you are interested in is getting from your mooring/anchorage to shore and back. Essentially in rib terms (or at least in terms of most ribnetters) this is just an auxilliary engine. The generally ribnet rule of thumb is 1HP per m of hull length for an aux. So a 3.3 should be OK. A bit bigger would be slightly better - but bear in mind that bigger will be more expensive and probably heavier.

In terms of hull - i think you have 3 options: (1) a totally soft bottomed boat (known as SIBs here). (2) a soft bottomed boat with floorboards (also known as a SIB) (3) a fibreglass hulled boat with inflatable tubes (what is generally considered a RIB here).

Depending how big your yacht is will influence which of these is sensible. But my experience of yacht tenders in category 1 above is that they are much less "secure feeling" than the sort of thing I think you have right now - but as cod says much easier to collapse and take with you.

Not sure if there is anyway you can try these afloat before you buy. Stepping down off a yacht can feel quite tippy in a lot of boats.

[GandyGoose]

Cheers. Your both right about the motor, and even if I didn't need more power then I would still want F-N controls at the very least. I'm happy with two-stroke. Maybe a 4 is the sensible minimum, or see what turns up either with the boat or second-hand.

Codprawn - that boat in your thread, is that a RIB, if that's not a rude question? I could only find "soft" Quicksilvers when I was looking around.

My Cat C comment was maybe a bit OTT - I just noticed that inflatables of around this size tend to be Cat C, so I guess I might question why something on offer might be only D. Our mooring could have a mile or more fetch at high tide, but I wouldn't really expect 2m waves.

[GandyGoose]

Oops should have said. I don't intend packing the boat away. It'll sit on a trolley when not in use, hopefully under cover. We couldn't fit it on board anyway, we have an Avon Redstart for use away from home.

I like the idea of a solid hull just on pure prejudice, not based on actual knowledge. Are there any disadvantages over an "airdeck" type boat, aside from a little weight and a little cost?

(I'll need to say SIB, won't I. I've only just learned to call RIBs RIBs, back in "my day" they were called Seariders, because those were the only ones we'd seen)

Tony S

[codprawn]

My Quicksilver is a SIB with a wooden floor. There is an inflatable keel which gives the bottom a sort of cathedral hull shape.Wooden floorboards are more rigid than an air floor but not as good as a true hard bottom boat.

As to coping with sea conditions we have crossed from swansea to Ilfracombe and back - something like 25 miles each way....

[Hugh Jardon]

Originally Posted by codprawn

My Quicksilver is a SIB with a wooden floor. There is an inflatable keel which gives the bottom a sort of cathedral hull shape.Wooden floorboards are more rigid than an air floor but not as good as a true hard bottom boat.

As to coping with sea conditions we have crossed from swansea to Ilfracombe and back - something like 25 miles each way....

was that a wise thing to do? in a 3.1m sib

[Poly]

Originally Posted by codprawn

There is an inflatable keel which gives the bottom a sort of cathedral hull shape.

do you mean cathedral hull? as in like a dory?

[Poly]

Originally Posted by Hugh Jardon

was that a wise thing to do? in a 3.1m sib

at what size of boat does that suddenly become a wise thing to do?

[edit: unless you meant - going back to Wales?]

[GuyP]

Originally Posted by codprawn

A 2.2hp is very small - I wouldn't go for less than a 7.5. Never kn ow when you need the extra grunt.

Originally Posted by Polwart

I don't think you will need to go as big a 7.5 HP though. Whilst it would be nice to think you could get the rib on the plane if you wished to do so lightly loaded

Having spent my teenage years mucking around in a varierty of SIBs, you'll need at least a 5hp to plane a 3m SIB when lightly loaded. However, when loaded and against tide you'll find the going slow and you'll chew up fuel, as you'll be giving it full throttle all the time. I'd go as big as is reasonable for your budget. There's very little difference price and weight (now they're all 4-stroke) wise between a 4.5hp and a 7.5 hp now anyway.

[codprawn]

Originally Posted by Hugh Jardon

was that a wise thing to do? in a 3.1m sib

Well we had flares - lifejackets - spare fuel - first aid kit - gps - even an anchor.

The most important thing was - it was a NICE day!!!

Remember with the 15hp we can cruise at about 15 - 20mph so didn't take too long. Didn't even use all of our 3 gallon main tank....

[Poly]

Originally Posted by GuyP

There's very little difference price and weight (now they're all 4-stroke) wise between a 4.5hp and a 7.5 hp now anyway.

I'll grant you I have just checked and most 4strokes are weighing the same in the 4-9.9 HP range regardless of power, however typically the 6HP version is £300 more expensive than the 4HP! Thats quite a lot of fuel...

...given the intended application (as a tender - and for pottering about) - I'm not convinced that the original questioner needs more power (although that depends on his feelings about going fast). Many, many yachtsmen are perfectly happy with 4HP and less on tenders (often quite heavily laden) for the relatively short journey to shore and back. Afterall he is managing with a 2.2 HP on a similar sized boat just now...

[Tony]

Hi
We have been using an ax2 with a 2.3 honda on the back.
Although very practical and light, wet backside and a very noisey engine has forced us into something a bit bigger. I am picking up a yam 4.hp on a Zodiac 2.6s with a new roll floor system Friday. That combo should give us plenty of go for just under a grand.
Tony

[GandyGoose]

Hmm. Not much on pros and cons of solid floor/keel (RIB) vs inflatable (SIB). Does that mean that most people don't see the point of a RIB that small, I mean no benefit over inflatable keel boats?

If that was the case, assuming a high pressure inflated keel, what about the choice between sectional ply or aluminium floor vs and inflatable floor? My thoughts are that I'd prefer the sectional floor. Easier to adapt if for example I want to add lashing eyes or something, and one less thing to pump up and worry about puncturing.

Thanks for the differing comments on engines. The ability to zip along is appealing, but I guess I'll need to decide how much I'm prepared to pay for that. It would open up some more uses from the boat.

I wasn't seriously intending to use the 2.2 except for trials - at the very least I'd want F-N controls, and a 4hp with F-N-R is probably the sensible minimum.

Tony S

[timboli]

I use a flatacraft force 3 RIB with a 3.5hp tohatsu as a tender,the 3.5 is light enough to get on board easily and the flatacraft tows well due to the heavier bottom but is a bit more of a struggle to push around full of kit with the outboard on(really tough with a 15 on the back).
The flatacraft will plane one up but any more weight and it is displacement speed only with the 3.5.
The flatacraft will convert to a safe sailing dinghy also.
The RIB is alot tougher and takes the knocks much better then a soft floor and will tow safer due to weight then an air floor inflatable(which I think could flip in high winds).
I have however had the RIB try to overtake me in a large following sea.

[Poly]

Originally Posted by GandyGoose

Hmm. Not much on pros and cons of solid floor/keel (RIB) vs inflatable (SIB). Does that mean that most people don't see the point of a RIB that small, I mean no benefit over inflatable keel boats?

I think that depends a little. If you do decide to put a big(ger) engine on it and use at speed then a RIB will probably be more comfortable (although if it is heavier may not go as fast with the same engine).

If it is for "pottering" and as a tender - I'm not sure it would be worth what I imagine is a fairly significant extra cost?

Generally people are inclined towards SIBs (with or without hard floors) because they are "easily" folded away and stored when not in use - that doesn't seem to be a concern/priority to you.

[jwalker]

GandyGoose, will you be landing on exposed beaches possibly subject to a bit of breaking water and will you need to haul the boat up the beach? If so, light is best because you'll need to escape the boat, grab it and get it out of the break pronto or the next wave is likely to fill it up. Inflatables and small ribs lie very close to the water, typically just a tube diameter above the surface. Also, a wee boat can become surprisingly heavy after carrying it 50mtrs. Wheels might be good.

[GandyGoose]

Cheers once again. The point about weight is well taken, although anything I'm looking at will probably be lighter than our 10' fibreglass dinghy, and easier to pull on/off the trolley as well.

Sticking with the "very small RIB" theme, there's the Zodiac Zoom 310 that I've seen in the flesh, the Flatacraft, and I see Valiant make a 3.00 basic RIB as well. Are there any other makes I should be looking at?

Tony S

[codprawn]

http://www.avoninflatables.co.uk/page/lei

The obvious choice!!!

[timboli]

I think the flatacraft option would have to be second hand!