Sib hp help

[D4V33]

Hi all, I’m toying with the idea of selling my boat and buying a sib, but unsure what size sib to buy. I think a 400-420 would be perfect, as I could easily launch it on the beach, but this would mean buying a short shaft outboard.

I have an 18hp long shaft tohatsu that I’d like to keep and use and know someone who is offering me a 470 sib at a good price.

I suppose what I’m asking is would an 18hp outboard be adequate for a 470 sib and just how much heavier and harder is this likely to be to launch?

Alternatively, is it possible to use a long shaft outboard on a smaller sib, something like the 400 carbon pro if I did something to jack up the transom height?

[Brinormeg]

Volaire 390 and a 20 efi is the max myself and fit young adult son can handle. Anything bigger would definitely be a trailer launch for us. Max speed was 24mph while playing about with different props.

I did see one guy who had extended his transom but there will be more knowledgable guys here to advise on that.

[D4V33]

Thanks Brinormeg,
If i could get away with using the long shaft on a smaller sib, that would be the perfect solution, as really want to get a 400.

[Steve509926]

There's no reason why you can't extend the transom to accommodate a long shaft but your "engineering" skills would be put to the test:-

https://www.rib.net/forum/f50/transo...ble-87202.html

I'd send dhaglund a PM and ask him how he got on.

[D4V33]

Originally Posted by Steve509926

There's no reason why you can't extend the transom to accommodate a long shaft but your "engineering" skills would be put to the test:-

https://www.rib.net/forum/f50/transo...ble-87202.html

I'd send dhaglund a PM and ask him how he got on.

Thanks for posting that link. Makes for an interesting read! I’d be more than capable of doing something similar.
It’s a hard decision to make. Raise the transom or buy a bigger heavier boat that will take the long shaft, but likely be under powered. I’m not sure if the 18hp would push the 470 or not.

All boils down to cost unfortunately.

[Steve509926]

Your 18hp will move a 470, not very fast with just you in it, and bloody slow with 3 on board. Also I don't know how many of you will be launching and retrieving the sib, but IMO a 470 sib will be very heavy, tiresome and if it was me I'd get fed up setting it up.

[Pikey Dave]

Originally Posted by D4V33

...I think a 400-420 would be perfect, as I could easily launch it on the beach,

Assuming you're thinking about hand launching & not trailer launching, think again. That's going to be a heavy, awkward lump to beach launch, more so to recover.

[Blankton]

I'm echoing what others have said. If you search the forums for these bigger sibs, nearly everyone ends up using a trailer, as they are too heavy to handle. Also if you look on ebay or Facebook at outfits for sale, the bigger sibs nearly always have a trailer. The good thing is that you see a lot for sale secondhand, often for a good price including launch trailer and engine.

I'd definitely think how you will use the boat, what the beach/slipway is like, how steep it is etc. before going any further. The big sibs are not that easy to handle. Even my 3m aluminium floor model can be awkward with the wrong kind of sand or too steep slipway.

[Fenlander]

Unless I've missed it you don't actually say if it is an alloy floor 470 you've been offered but I assume so. Also I'm not sure if you are hoping to transom wheel launch from a beach or trailer launch on hard sand. And finally is it just you or always with mates?

I had a 3.5m alloy floor and in truth a 15hp was marginal for that so anything close to 4.7m and I reckon 25hp would be more suited... if you use a trailer/trolley or are super strong.

Re keeping the long shaft Tohatsu I know they are a great motor but personally I'm not keen on extending a transom that far and don't like the OB powerhead CofG being so high. If it's tidy it should sell really well and enable you to get a motor to suit your new SIB.

[Pikey Dave]

You don't say what your current boat is. If it's a RIB on a trailer, you're not going to gain anything (apart from a bad back) by going to a hand launched SIB, especially if the SIB ends up having to go on a trailer.

[Steve509926]

The OP has asked a similar question before so I have assumed not much had changed.

https://www.rib.net/forum/f50/sib-size-help-89665.html

[D4V33]

Thanks for all the replies. I’ve been at work, so not had a chance to reply. As in the link Steve posted above, I still own a Dory13 that i trailer launch with my son on the beach. It’s a great boat and I’ll be sad to sell it. The dory launches easily, hand pushed into water and although heavy, I’m just able to drag it back out myself, although tend to just tie a rope to the jocky wheel and pull it up the beach and hook it to the car. All fell through last year when I had a mini stroke, but back to good health and eager to get back out.

The reason I keep considering a sib, is due to storage. I have a place for my boat just now, but won’t have it for ever and I don’t have a driveway at my home. It does seem a pain, having to build and breakdown a sib, but it’s a small price to pay if it gets me on the water.

[D4V33]

To answer a few other of your questions, I like the idea of being able to pull a sib into the water on transom wheel.

When it’s time to retrieve the dory from the water, my son has to hold the boat by the water while I go get the car and hook on the trailer. If the weather is nice and the beach is busy, the car can be parked a fair distance away. The idea of just dropping the transom wheels and pulling it onto the beach seems great.

There’s also the possibility of me fabricating a light weight trailer that I can break down and keep in the garden when the sib is not in use. This would allow me to keep the boat on the trailer when I’m off work in the summer. (I only need to tow it about a quarter mile to the beach from my house).

The sun would preferably be with aluminium floor.

It’s only ever me and one other person (usually my son) on the boat fishing.

[Steve509926]

Originally Posted by D4V33

The idea of just dropping the transom wheels and pulling it onto the beach seems great.

Before you spend your hard earned money, make sure you see a 4mtr ally sib in the flesh, preferably with an ob attached. Then think about pulling that up a soft sand beach. Hopefully you'll still feel confident that you can manage it. I'm pretty fit and healthy, so is my better half, and I wouldn't even consider a 4mtr ally sib, it's just far too heavy to manhandle. Make things hard for yourself - size, weight, assembly, disassembly, the less you will want to go out on the water.
"It does seem a pain, having to build and breakdown a sib, but it’s a small price to pay if it gets me on the water" , I'd question if you'll be saying "it's a small price to pay " in 12 months time.
The easier you make things, the more you will want to get out on the water.

[Pikey Dave]

My personal opinion is that your current setup with the Dory, would seem to suit your needs better than a SIB would. I think that the solution to your perceived problem will only make the problem worse. I’d stick with what you’ve got & solve the potential storage issue for your current setup. If you start dragging a SIB up a beach, it won’t last long.

[Peter_C]

Anything around 4 meters is going to be a heavy pig pulling it out of the water. It can be done and I have done it lots of times, but it takes a couple of strong folks with 3 or more being better.

Setup and breakdown of a larger SIB is just not fun. Small ones with 9.9hp outboards are not a big deal, just take a little time. If you make all electronics, anchor, etc easily removable it helps.

[D4V33]

Originally Posted by Steve509926

Before you spend your hard earned money, make sure you see a 4mtr ally sib in the flesh, preferably with an ob attached. Then think about pulling that up a soft sand beach. Hopefully you'll still feel confident that you can manage it. I'm pretty fit and healthy, so is my better half, and I wouldn't even consider a 4mtr ally sib, it's just far too heavy to manhandle. Make things hard for yourself - size, weight, assembly, disassembly, the less you will want to go out on the water.
"It does seem a pain, having to build and breakdown a sib, but it’s a small price to pay if it gets me on the water" , I'd question if you'll be saying "it's a small price to pay " in 12 months time.
The easier you make things, the more you will want to get out on the water.

Many thanks for the reply. Your right, I really do need to see one and judge the actual weight. I suppose Im just stupidly assuming that an inflatable will be much lighter and easier to launch than the glass fibre boat I have, but have no experience with sibs in the slightest, which is making me now think I should hold off until I can afford a 9.8hp short shaft to put on something a bit smaller.

[D4V33]

Originally Posted by Pikey Dave

My personal opinion is that your current setup with the Dory, would seem to suit your needs better than a SIB would. I think that the solution to your perceived problem will only make the problem worse. I’d stick with what you’ve got & solve the potential storage issue for your current setup. If you start dragging a SIB up a beach, it won’t last long.

My current setup is great and works well for me, but the storage issue will be a problem in the future.

I’m trying to sort something out, but not holding my breath. I may just have to bite the bullet and sell it and try saving for something smaller.

Thanks for taking the time to reply

[D4V33]

Originally Posted by Peter_C

Anything around 4 meters is going to be a heavy pig pulling it out of the water. It can be done and I have done it lots of times, but it takes a couple of strong folks with 3 or more being better.

Setup and breakdown of a larger SIB is just not fun. Small ones with 9.9hp outboards are not a big deal, just take a little time. If you make all electronics, anchor, etc easily removable it helps.

Sound like everyone is in agreement on the hassle a large sib adds to the mix.

Your suggestion of the smaller sib seems the only option.

Many thanks

[Steve509926]

Originally Posted by D4V33

I should hold off until I can afford a 9.8hp short shaft to put on something a bit smaller.

Not necessarily a 9.8.

A good used 15hp 2 stroke short shaft on the back of a 3.6 sib would probably be ideal, and why ally? there are loads of sibbers fish from an airdeck sib.