Dinghies.. What's the Current Wisdom?

[downunder]

Originally Posted by Jim Cate

G'Day Vic,

Ask a simple question, and look at the divergent answers that appear!

Well, here's one that hasn't yet emerged: We have a Gemini 3.5 Meter aluminium hulled RIB. The hull is now 8+ years old,the tubes 6+ (difference being that the dink was stolen and the tubes burned at around 2 years). The hull for these is made by Swift up in the Gold Coast, and the hypalon comes from South Africa. Don't know if they are available in the States, though.

At any rate we are very happy with the performance of the dinghy (15 hp Yamaha 2/s). The hull has a flat internal floor, separate from the actual hull, integral transom supports and welded attachment points for tow line/painter, lifting bridle and (should it be of interest) skiing things. Contrary to what others report, after all these years the powder coating on the hull is still good... save the scrapes on the bottom where we've mistreated it. And even those now bare spots have not corroded. Even the areas where the powdercoat was burned off have survived fine! The final really good news is that the bare dinghy (remember, 3.5 meters long) weighs 47 kilos!

The bad news is that the Hypalon is of fairly poor quality, and it has worn in high use areas. The attachments for the "safety line" and oar storage were made with fabric loops which died from sun exposure in less than a year. The seat and rowlocks are so far forward that when rowing the stern blows downwind pretty easily. Bottom line is that we might not buy another one, but will have new tubes installed before long (about half the cost of a new dink).

On the other hand, the Swift company (which obviously uses the same hull) provides better Hypalon and a pretty similar design for the tubes. It weighs a bit more because of this, but seems to have a better longevity factor. Again, I don't know about availability in the states. For me, the big deal for these dinks is the light weight for the size... and Vic, you will be happier with a bigger dink... trust me on that!

As others have said, when cruising, your dinghy is a really important part of your life so a good choice, one that fits your usage is a big deal.

Good luck, mate!

Jim

Vic,

The majority of RIB's used in the Charter industry in Queensland are Hyplon with Alumimun bottoms. More durable but lighter than a fibreglass RIB but seems from posts not as available in States as fibreglass.

Jim's posts have been born out by long experience. NIAD is prossibly the premium product but may not be readily available in USA. I look foward to follow your decision.

Cheers

[Auzzee]

I have just downsized my boat from 55' to 37' and want to buy a new dinghy. An RIB (My last was an Avon 10'6") is not an option as I won't carry it on deck whilst offshore.

I'm looking at a roll up with a slatted roll up floor. This thread has helped a lot. Thanks.

[cosmic pete]

just my 2 cents worth in oz you cant go past a 10 ft poly craft unsinkable , fairly crock proof handy in fnq ,25 knots with a 15 hp outboard and rated for 250 kilos , it has survived 4 years of been pulled up on a rocky beach every day and did i mention stable ?? can stand 3 full grown blokes on the gunnels and wont tip over ,i use it as a ute carrys everything i need out to boat and tows well with a strong tow point , only down side is it weighs 80kg hull only

[Andrew Troup]

One of the problems with coatings on alu is that any scratches which get through the coating mean that concentrated corrosion cells are set up at that location. The adjacent aluminium, under the coating, is deprived of oxygen to maintain a protective layer, so the corrosion cell spreads out, burrowing under and peeling back the coating like something from a bad 50s horror movie, unless the adhesion is exceptional, which is difficult to ensure with aluminium.

Which is why unpainted is one of the best options for alu, or if you don't go for the utilitarian look, a good option might be some sort of passivation along the lines of a chromate conversion coating, such as one of the Alodine products. They tend to produce that 'military spec' dull golden tinge - it's a bit like staining timber as opposed to painting it. Normally it's done in big tanks (but without the electric current associated with anodising) but there is at least one option which can be brush or spray applied. Google "Alodine" - the manufacturer is "Henkel"

You can get touch-up felt-tip applicators for one of their coating systems...

I'm thinking of trialing this as a coating in the bilges of an alu sailboat hull. Anyone tried it already?

[noelex 77]

This is my take on RIBs

By from the best manufacturer you can. It's very difficult to asses the quality and they fail in places like the join between the fabric and hull. A good manufacturer will not have these problems.
The best seem to be
NIAD
AB
Carabie
But there are other good ones. Ask other before you buy the brand.

The best floor is
Aluminium
Fiberglass
Plastic.
In that order. Aluminium is the strongest and lightest. It will survive being dragged over coral and rocks the best. I never heard of someone puncturing the bottom in an aluminium rib (I am not saying it won't happen, just it must be rare if I have not met someone who has done it). If its a marine grade aluminium (check) it does not need any paint. If painted the paint will come off,but there won't be any corrosion problems.
Fiberglass is the next best. It is the least puncture resistant and it is the heaviest, if you use it full time you are very likely to put a hole in the bottom at some stage, but it is easily repaired.
Plastic is lighter than fiberglass and more puncture resistant. If it is is punctured however it is almost impossible to repair and after a few failed attempts most people give up and get a new RIB. (Some of the ordinary rigid dinghies use very thick plastic and you are unlikely to ever puncture these, but it makes them heavy and they are designed as displacement only)

Tubes
Hypalon
PVC

Hypalon is much better in a sunny environment. Some PVCs have improved remarkably over the last few years and there is evidence that the good ones will have a reasonable life (15 years or so). The bad PVCs are terrible and go sticky in only 12 months. Many cruisers make a canvas cover for the tubes. Even Hypalon is effected by strong UV.

[downunder]

Excellent summary of RIB's.

Totally agree the Al hulls will take more abuse than fibreglass.

[ranger58sb]

Originally Posted by jeremiason

Sorry Chris you right... I was ranting about the plastic WB boat, which is a good price and durable, but very slow as compared to RIBS

And the Genesis even has beer can holders! What will they think of next

Exactly! And you can even double the beer can holders simply by adding another seat in the second slot position!

-Chris

[Vasco]

Find the Porta Bote!!

[VirtualVagabond]

I've just had a look at NAIAD's website and they look very good.
No sign of pricing but they look like they will be expensive.

Vic

[noelex 77]

Originally Posted by VirtualVagabond

I've just had a look at NAIAD's website and they look very good.
No sign of pricing but they look like they will be expensive.

Vic

I think they make the best, or at least the toughest RIBs. I suspect they will be expensive in your location. They are big things to transport even when the tubes are deflated.

[donradcliffe]

While we are on the subject, how about any recent feedback on dinghies with blow up floors?? All I ever heard was horror stories-- the blow up floors failed after a while and could not be repaired.

[Rocketman]

Originally Posted by donradcliffe

While we are on the subject, how about any recent feedback on dinghies with blow up floors?? All I ever heard was horror stories-- the blow up floors failed after a while and could not be repaired.

If you can find one with a good reputation I would concider one. When they are inflated and not leaking, they are a great. My Mercury as posted earlier, started leaking in the seems after a couple of years, and Mercury will not warranty it as the floor is made of PVC and only has a one year warranty on the floor, even though when they sold it to me I swear they told me 10 years, I didn't read the fine print when I bought it, I took the salesman's word. In reality he probably thought it was 10 years, but it didn't help me.

There may be other brands that have a good air floor option with a good reputation, but if concidering a Mercury, stay away from the air floor unless you are willing to replace it every couple of years.

[Jim Cate]

G'Day agin Vic,

Naiads are indeed sturdy, but very heavy... very! That ruled them out for us.

Cheers,

Jim

[VirtualVagabond]

Originally Posted by Jim Cate

G'Day agin Vic,

Naiads are indeed sturdy, but very heavy... very! That ruled them out for us.

Cheers,

Jim

Hi Jim,
That would rule it out for us too. It's not just the weight on the davits, it's being able to pull it up on shore too.
I haven't found much representation for them here either.

From the thread so far it looks like we'd be ok with Achilles, AB, Genesis (Walker Bay), or Mercury, depending on who gives us the best deal.

I really think we need to revise our length paramaters to 10' - 11', rather than 9'.

I feel decision time approaching

Vic

[CarinaPDX]

I am still using my 1996 AB 260 FG RIB and am still quite happy with it. Once, lowering it onto the foredeck a stanchion punched a hole in the hull, which was easily repaired with glass cloth and epoxy. I will probably go with an aluminum RIB such as the 9' AB Lammina for the next dinghy.

One reason not mentioned to like RIBs is that they make great tugboats - I have pushed 50'+ sailboats and powerboats with my Merc 15hp 2 stroke. Slow, but workable. Whether driving against the transom or pushing the bow over the dinghy won't scratch the tow.

As the previous poster noted, the weight is (for me) more important on the beach than lifting the boat with the halyard/winch. Thus I am looking at aluminum.

Until recently I was using a Racor 320 (mounted on the transom) to separate water out of the gasoline. Unfortunately it had a strong tendency to corrode (both the housing and the replaceable filter). So instead I replaced the outboard's internal fuel filter (really just a plastic screen) with a Racor 025-02 with the water-separating filter element. Much tidier.

It seems to me that one major reason for getting a longer dinghy is that it takes less horsepower to get on a plane. With my 8 1/2' the 15hp struggles to get 3 people up on a plane - a 12' usually is able to take 4 up on a plane easily with that much power.

There is a fore-aft trim issue with most RIBs (particularly light ones) - I often have to ask crew to lean forward to help hold the bow down while trying to plane. So I use a Moeller triangular 6 gallon bow tank mounted far forward to help. Edit: I also have fins mounted to the cavitation plate, which helps a bit. I would go with the one piece design the next time.

Have fun with the new toy...

Greg