DIY Sealegs

[jakew009]

Has anyone ever tried making a diy version of a sealegs rib?

I’m thinking it would solve most of my problems (being so limited by tides when I can launch and recover) but:

- sealegs ribs are stupidly expensive
- on the old ones I could afford I don’t like the engines (evinrudes) or the layouts

I’m thinking perhaps a 8-9m diesel sterndrive rib and retrofitting fitting it with some folding up wheels sea legs style.
Perhaps modify the diesel to run on land with cooling water and a radiator and then don’t need a second engine..?

Anyone ever done anything remotely like this?

I did think about trying to go electric but hydraulic wheel motors will be much easier..

Would the hull need reinforcing?

[GuyC]

There was a chap on the Isle of Wight who had added tracks from a mini digger on to an aluminium hard boat. It did enable him to drive up some quite steep shingle beaches. It was still a separate power pack. IIRC they retracted into the hull. There was a fair amount of engineering required. Iguana Boats are a very expensive version of this.

I would imagine that the hull would need some reinforcement for local loads rather than global ones.

[ShinyShoe]

They are a hellish compromise.

Would it really help your tides? What's the terrain. Where are you storing the beast of a rib ashore.

[lakelandterrier]

Ii would be a lot easier and cheaper to find a different berth solution if you are finding your tidal constraints too limiting, and it wouldn't affect your RIB's sea-keeping or performance.

[jakew009]

Originally Posted by GuyC

There was a chap on the Isle of Wight who had added tracks from a mini digger on to an aluminium hard boat. It did enable him to drive up some quite steep shingle beaches. It was still a separate power pack. IIRC they retracted into the hull. There was a fair amount of engineering required. Iguana Boats are a very expensive version of this.

I would imagine that the hull would need some reinforcement for local loads rather than global ones.

Do you have any more detail on it? Was it online?

I’m wondering if building an aluminium hull might be easier than converting an existing boat. Hmmm

[jakew009]

Originally Posted by ShinyShoe

They are a hellish compromise.

Would it really help your tides? What's the terrain. Where are you storing the beast of a rib ashore.

I could simply park up and drive the boat down the slipway and out the estuary until I got to the sea. At the moment it’s +/- 2 hours of high tide and there are basically no other mooring options.

Why would it be a compromise? How do they effect the sea keeping? I appreciate they add some weight

[Poly]

Originally Posted by jakew009

I could simply park up and drive the boat down the slipway and out the estuary until I got to the sea.

what's beyond the slipway until you get to floating depth? mud, soft sand, shells or loose shingle - I suspect you'll sink in; hard packed sand, smooth rock, etc - you might be ok; big rocks you might find the small wheels aren't up to the job.

If it could solve a lot of people's problems, have no compromises (like extra weight, maintenance etc) and be delivered much cheaper I'm sure someone would be copying them by now.

Are there no marinas, moorings, etc?

[jakew009]

Originally Posted by Poly

what's beyond the slipway until you get to floating depth? mud, soft sand, shells or loose shingle - I suspect you'll sink in; hard packed sand, smooth rock, etc - you might be ok; big rocks you might find the small wheels aren't up to the job.

If it could solve a lot of people's problems, have no compromises (like extra weight, maintenance etc) and be delivered much cheaper I'm sure someone would be copying them by now.

Are there no marinas, moorings, etc?

Hard sand, you could drive a Land Rover all the way out.

Sealegs have sold 1500 boats since 2005 so they must be doing something right.

No marinas, moorings but they dry so it’s not really much of an improvement.

I agree I don’t understand why they are not more common.

[jeffstevens763@g]

Decent quad ?

[GuyC]

Originally Posted by jakew009

Do you have any more detail on it? Was it online?

I’m wondering if building an aluminium hull might be easier than converting an existing boat. Hmmm

These were taken in 2007.

For a one off, aluminium is quite a good material to build in. There are quite a few kit boat plans on the internet.

For example:

Aluminum RIBS (Rigid Inflatable Boat) | Aluminum Boat Plans & Designs by Specmar

[jakew009]

Originally Posted by GuyC

These were taken in 2007.

For a one off, aluminium is quite a good material to build in. There are quite a few kit boat plans on the internet.

For example:

Aluminum RIBS (Rigid Inflatable Boat) | Aluminum Boat Plans & Designs by Specmar

It’s certainly not beautiful

I was looking at the 8.5m specmar aluminium rib earlier. Hmmmmm

[Lee argyle]

Originally Posted by jakew009

I agree I don’t understand why they are not more common.

Maybe,
Cost
Compromised hull / weight
More to go wrong (2nd engine, hydraulics, legs and controls)
Limited market


I fully understand if u own a remote island ( no harbour/slipway etc ) and have no other means of accessing it then a sealegs style boat works - otherwise.........

[Ferryman]

The concept is brilliant, if I had different boating needs I would have bought a Sealegs - I tried one once at the Southampton boat show. To be able to land almost anywhere, even if it’s on an open beach for a bbq or an ice cream OR to be able to wild camp and not worry about the boat.........
I love a project, but to diy one of these is on a different scale!!
Sealegs layouts are definitely a bit dodgy, I agree but much easier to change than fitting a reliable powered wheel system to a rib and I always liked Modern Evinrudes.

[jakew009]

Originally Posted by Ferryman

The concept is brilliant, if I had different boating needs I would have bought a Sealegs - I tried one once at the Southampton boat show. To be able to land almost anywhere, even if it’s on an open beach for a bbq or an ice cream OR to be able to wild camp and not worry about the boat.........
I love a project, but to diy one of these is on a different scale!!
Sealegs layouts are definitely a bit dodgy, I agree but much easier to change than fitting a reliable powered wheel system to a rib and I always liked Modern Evinrudes.

I need a new project

Anyone ever built an aluminium boat before? Doesn’t look terribly difficult

This is almost perfect if it was made a little bit narrower so it is legal to tow: 8.5 Meter RIB (1314) | Aluminum Boat Plans & Designs by Specmar

Cut and shut the transom to fit some bootleg Sealegs on.

This dude did it and he cut it all by hand my boat build so far for all who are interested | Fishing - Fishwrecked.com - Fishing WA. Fishing Photos & Videos

[Ferryman]

Good luck - it’s been fun watching The Gurnard turn his sib into an inflatable topper......a bit more doable?? I’m just saying!! 🤷[emoji16]

[GuyC]

If you buy the cut part files with the correct info on them, which is possibly what the Specmar files will give you, someone like Aalco can cut all the plate and supply the sections. It's then like a 3D jigsaw.

Highfield seem to manage it although when I last looked at them a few years ago, some of the welding was a bit iffy.

Unlss you are a dab hand at ali welding, I'd probably employ someone to do the welding and then do the fit out yourself (minus chart table obviously)

Good luck

[jakew009]

Originally Posted by GuyC

If you buy the cut part files with the correct info on them, which is possibly what the Specmar files will give you, someone like Aalco can cut all the plate and supply the sections. It's then like a 3D jigsaw.

Highfield seem to manage it although when I last looked at them a few years ago, some of the welding was a bit iffy.

Unlss you are a dab hand at ali welding, I'd probably employ someone to do the welding and then do the fit out yourself (minus chart table obviously)

Good luck

We do lots of fabrication work in my business so I’m not too worried about getting it lasered and welding it together. Not done mix Ali before but looks like pulse mig is the way to do it.

I was thinking of possibly a kind of sport cruiser esque cabin rib. Maybe I could have a chart table and some compasses after all

I was originally thinking diesel inboard but with red diesel rules changing and the hassle of inboards, maybe a pair of outboards would be better. More space inside.

[GuyC]

Sadly I can't weld so I can't comment on the welding techniques. I know the Aussies router cut their plate rather than water jet as it leaves a better edge for welding.

[paulbrown22]

Maybe just double check some specifications from yacht/boat builders who build in aluminium, as some grades of aluminium are better in salt water than others.

Our Alubat Ovni sailing yacht is built from 5083 and 5086 H111 aluminium, and they use a combination of MIG and TIG in Argon.

[Poly]

Originally Posted by jakew009

Hard sand, you could drive a Land Rover all the way out.

An old landy or tractor would be a lot cheaper than sealegs.

Sealegs have sold 1500 boats since 2005 so they must be doing something right.

My point was in that same period hundreds of rib makers have all sold thousands of boats - and none seem to have been tempted to copy them. If there was big profit margins and high demand ( =solves a real problem for lots of people) surely someone would have - either from scratch or as a retrofit option. In fact if it was simple to add to other boats - sealegs would probably supply kits...

No marinas, moorings but they dry so it’s not really much of an improvement.

you'll probably have to do what the rest of us do then - drive a bit further to more convenient facilities when the tide is wrong.

agree I don’t understand why they are not more common.

Because if you have £100k for a rib (and its fuel costs), you probably have the money to store it in a marina/drystack or access to an all/most tides slipway.

Go for the DIY option by all means - people here will be fascinated to see how it goes - but keep in mind that as a homebuilt boat you will be unable to sell it for at least 5 years from completion.