Wharram Pahi catamarans

[boatchippy]

Hi

Looking for as much info as possible on Wharram Pahi cats.
Has anyone using the forum built one?


Cheers

[Wild Dingo]

You have gone to Wharrams site havent you? they also have a forum... very biased but then thats what you would expect there but a lot of interesting stuff

Are you looking at that one at flatducks? $6000 seems pretty damned good in my book

[Boatmik]

Howdy,

I've sailed both on and alongside a 31 Pahi more than a few times. Robert Ayliffe had built one while he was a teacher before he started Duck Flat and did not know a huge amount about sailing and different types of boats.

Robert's opinion now is that if he had known more about boats at the time he may have made a different decision.

My feeling is that the Pahis are more or less competent in a Tahiti Ketch sort of way. They are not particularly fast and are not very good upwind - compared to modern cats and many modern monohulls. They are unwieldy and slow to manouvre.

Occasionally they can get the wind just at the right angle and really crank along - but most modern boats crank along whatever the angle of the wind.

But on the other hand long voyages have been made by many and some have survived nasty storms.

Personally I feel that a boat that doesn't go upwind well reduces the safety factor somewhat when cruising - but many people work around that with superior planning, good seamanship and a bit of luck.

The building method appears fine - modern enough to cut out lots of labour - bit it all depends on how much stuff you want to fit inside (but that applies to any boat).

The Pahi 31 had OK accommodation - but many modern cats of similar size have bridgedecks to increase the interior volume enormously (as well as building time - surface area equals labour). Most of Wharram's smaller boats - under 30' - have very poor accomodation for their size compared to either monos or modern multis.

It is well worth actually measuring up the spaces shown in the plans by careful scaling to real size - don't trust the drawings of interiors in his brochures - the people are often drawn in small and grass skirts mean endless sweeping up down below.

MIK

[mark_dugong]

Hi,
I am new to this forum but anyway here goes.
I built a Pahi 31 about the same time as Rob Ayliffe when I was in Adelaide and sailed with him from Kangaroo Is to Adelaide on it. Funny enough I went on and built a small Sharpie in the '90's over here on the NSW northcoast only mine was a Bolger-25 gaff yawl-a lightly modified "Jesse Cooper" design with Bolger's approval-it still provides me with a lot of fun and adventures.
Anyway I guess I am one of those people attracted to the less conventional. I sailed my Pahi 31 from Adelaide to the North coast of NSW, where I sold her.
I found the Pahi 31 an excellant sailing cat which would go to windward when needed although not pointing as high as a mono. For the price you paid you had a good fast shallow draft vessel which was a joy to sail downwind, which is the only way we gentlemen go! Not quite as fast as similar size high cost cats, which often will not go to windward at all and instead rely on their motors.
Anyway I sold mine much too soon as I went back to Uni and then I built a Bolger square yacht as I was after some mobile low income housing as well as sailing. I have a permnent mooring on the Brunswick River and my yacht 'Dugong' is currently on anchor in the Great Sandy Straits for the winter.
I feel the the Wharram Tiki 30 is probably another option to consider around that size and reportedly easier and cheaper to build with a deck pod option.

[Boatmik]

Howdy Mark,

Absolutely true right down to the nice feeling travelling downwind in the Pahi - no fuss and reasonable covering of ground.

However I don't agree with

Not quite as fast as similar size high cost cats, which often will not go to windward at all and instead rely on their motors

I have been astounded by the few races I have done in modern multis. They are so much faster than monohulls on all points including upwind that even I as a "died in the wool" monohull sailor would seriously consider a modern multi for cruising or racing offshore - you can cover serious ground upwind and down.

One of the boats I sailed was a Kelsall 32 set up for cruising with full cruising payload. It pointed within a few degrees of a good mono but was about 50% faster at speeds of around 9 knots in 15 knots of breeze.

The other experience i had in a race on a little 24ft Dragonfly tri in Qld gave us upwind speeds of 7 to 8 knots - even though we were having serious problems with the centreboard and downwind we were in the 14 to 16 knots range with no drama - just relaxed sailing - until we decided to pop up the kite and it got quite exciting at around 20 to 22 knots.

Upwind is where the big performance increases have been made in the last 20 years with multihulls.

I agree there are some modern boats that need to use their motors to get upwind but there are plenty that so completely outperform monohulls on that point that comparisons are meaningless - and I'm talking middle of the road cruising multis.

Best wishes
MIK

[mark_dugong]

Hi Mik,
I have to bow to your probably quite considerably broader experience Mik, however I do still feel the Wharrams are still in the category of fast cruising yachts with good value for money in construction.
As you say, the modern cruising multihull has a much better windward performance than decades ago, they also have much higher construction costs, especially the GRP designs.
Unfortunately many still have to my eye, much too much windage which is symptomatic of many multis I have seen on the Moreton Bay and Queensland waterways. Wharram also (with 50 yrs of design and sailing experience) says the same in an article on windage and performance parameters on his website-I can forward the article if you can't locate it.
But far from taking up your time, yes I agree there are good high performance multis out there and they are not neccessarily Wharrams.
Look forward to reading yours and many others excellant posts on a brilliant website.
Cheers
Mark

[boatchippy]

Thanks for the replies fellas

I'm in the process of gathering information on Warram as I'm looking at building a Pahi 63.
Coming from a traditional timber boat background (carvel), these craft though very simple in construction are somewhat exotic to me .

Anyhow. I have been asked to build this cat which will be used as a commercial boat for charters/tourist purposes, (using Warram specs) to survey.

If the job is given the green light, I'm told it will be the first pahi 63 built in Australia, as I believe there are only six or seven of this kind in the world.

They look a little prettier(more like a boat) and user friendly than your standard 'uglo cat' (I'm not a multihull fan), so I'm happy to consider taking on this project.

Cheers

[Boatmik]

Howdy BoatChippy,

I've been involved in the fringes of getting a couple of multis through survey.

Both have been a little bit more difficult than they should have been.

The trick is to get the authorities to sign off on things as you go as far as possible. And keep a diary of phonecalls and all paperwork that you receive from them

With the two I was involved with the boats got quite close to being fitted out only to find that the authorities suddenly decided that the hull skins needed to be 6mm thicker.

The generally antiquated rules used for judging timber construction are set up around monohulls and the crazy thing is that multis are expected to conform.

Or at least used to - the rules have changed somewhat but I would still strongly suggest that you try to get them to sign off on the plans - preferably literally - with a signature on a piece of paper or an email with someone's name at the bottom - print it and file it in a safe place.

With one of the boats they stipulated that the hull had to be beefed up with glass - which added a huge amount of cost and weight to the structure.

We found out later that the actual problem was the hull thickness and we could have used timber which would have been less than half the weight and considerably cheaper to beef up the bottom only - the sides were actually OK. Still lots of labour but...

The second boat they tried the same thing but we had a better idea of the actual requirements so were able to lead them down the preferred path.

So I would be asking a specific question about whether the hull thickness specified by Wharram is OK - on paper or by email - and retain this approach through the building process

MIK

[Boatmik]

Hi Mik,
I have to bow to your probably quite considerably broader experience Mik, however I do still feel the Wharrams are still in the category of fast cruising yachts with good value for money in construction.

I would agree completely with good value for money if you don't consider the generally poor resale. For someone who is wanting an inexpensive cruising boat of a type that has been shown to be quite seaworthy then they are a good choice.

But performance, particularly upwind is weak.

On the other hand I think the Pahis, in particular, are very pretty boats - and strikingly original.

As you say, the modern cruising multihull has a much better windward performance than decades ago, they also have much higher construction costs, especially the GRP designs.

Agree that there has been a big trend to making multis more complicated, but some designers that are doing modern, quick boats without going too big or complicated. Derek Kelsall - who still has plans for wooden boats and the "Woods Design" multihulls are nice in the smaller sizes.

Unfortunately many still have to my eye, much too much windage which is symptomatic of many multis I have seen on the Moreton Bay and Queensland waterways. Wharram also (with 50 yrs of design and sailing experience) says the same in an article on windage and performance parameters on his website-I can forward the article if you can't locate it.

I have read quite a lot of James' stuff over the years so I pretty well know what he will be saying. I like his aesthetic but whenever he moves into more theoretical areas he tends to be very self serving. All of us who sell plans are to some extent - but Wharram is one of the few who attempts to move the facts to fit his arguments.

I remember writing a reply to a Cruising Helmsman article he put together about multihull stability a decade or more ago. He was talking about a boat A (something like a wharram) and a boat B that typified what he said was a "common cruising multi of that time with some of the primary measurements of each.

Then a stability screening formula was applied.

I simply drew boat A and boat B up to scale - and quickly saw that the "modern cruising multi" that he was talking about was so extreme in sail area and mast height that it was way beyond what even the racers were doing at the time. It would have been a very "dangerous" boat for cruising but it wasn't representative of any cruising boats at the time or maybe even now.

In the end every design is worth exactly whatever it is worth - with strengths and weaknesses but Wharram is very loath to acknowledge the strengths of other design routes or acknowledge the limitations of his own.

But on the other hand he's got squillions of people out on the water doing really great stuff.

So maybe in the end a designer too is worth exactly whatever he/she is worth - with strengths and weaknesses as well.

And that goes for my work too.

Best wishes and glad to have you aboard

Michael

[mark_dugong]

Hi Boatmik,
I have a problem with you describing the Wharram cats as having a weak performance particularly to windward. I mean weak compared to what?
I know if I was off a lee shore with 35-45kts in a strong well built wharram, it would get me to windward-not as well as some but well enough to save myself and vessel. I have seen and listened to well documented accounts of Wharram catamarans surviving cyclones and cyclonic conditions-is that a weak performance?-you just had to look at the Sydney to Hobart of a few years ago as a big Bass Strait low pressure wiped out half the fleet of "high performance yachts". Were those weak performances or what? No reflection on the sad loss of life of those involved
I certainly would still seriously question the abilities of some of the more modern catamarans in this fundamental seaworthiness of windward ability and being able to survive extreme events.
Here is the link to Wharrams page on windage which as you know has a lot to do with windward ability- http://www.wharram.com/freeboard.html
The claim Wharram likes to make about his designs is that they are "catamarans that are remarkably sea-worthy, secure and very unique."
And that I believe is a statement that has credibility and there are probably more designs out there by that guy Wharram with happy owners doing more sea voyages than any other cat around.
To Boatchippy I think there have been two Pahi 63's built in Australia and one was quite heavily modified with the intention of being a research/charter vessel.
It appears Wharrams own preference for yacht charter work is his Islander 55 design and I think the Pahi 63 is more intended for ocean crossings-thats only my opinion though.
Thanks
Mark
ps when can we start talking about Bolger designs?

[bitingmidge]

Giday Mark,
I have certainly posted a few posts round here that give some peope (eh Dingo? ) the impression that I am anti-Wharram. I'm not, but I also won't resile from the fact that there are MANY better performing boats.

The boat in question is being built for Charter/Tourist operation, so none of the arguments put forward below are even relevant. If it is true to type it will be a motor boat with a bit of downhill motor-sailing, and as such, if it can be built in survey will undoubtedly do an admirable job for the purpose it was intended.

However, if you'll allow me to address your notes one at a time, I'll try to put my perspective.

Hi Boatmik,
I have a problem with you describing the Wharram cats as having a weak performance particularly to windward. I mean weak compared to what?

Whatever Boatmik meant, I would say weak compared to any competently designed multi.
What do you mean by "performance"?
Have you ever wondered why you never see Wharram's at the top end of a racing fleet? In fact you never see them racing, period.

That's simply because they are weak performers in the context Mik was using. If they were great performers, you'd see dozens of them out there, and they'd be competing with the vintage plywood trailer tri's (which are quite moderate performers even now).

Or you'd see racing boats incorporating Wharram ideas. (Oops, is that why racing boats eliminate windage! )

I know if I was off a lee shore with 35-45kts in a strong well built wharram, it would get me to windward-not as well as some but well enough to save myself and vessel.

Having once happily sailed from the Whitundays to Brisbane on a modern (mid-eighties) lightweight thirty foot cat entirely to windward in around 30 knots average South Easterly, and having experienced numerous storms at sea in a variety of multis, I don't know that I'd bet on any of them getting you off a lee shore in 45 knots! It depends I suppose on how far off-shore you start and how big the gusts were! Sometimes it's good to have great ground tackle.

I have stood on the cabin of my boat, in the Bribie Passage, with two foot of foam washing over the top, and there was no way I was going to up anchor and sail off! Admittedly it was more like 65 knots, but it's all a bit academic when survival conditions arrive.

I doubt that any boat without a true foil centreboard/keel would have that capablilty, but some may correct me.

I have seen and listened to well documented accounts of Wharram catamarans surviving cyclones and cyclonic conditions-is that a weak performance?-you just had to look at the Sydney to Hobart of a few years ago as a big Bass Strait low pressure wiped out half the fleet of "high performance yachts". Were those weak performances or what?

Don't mix "performance" with "survivability". Much as I don't like liferafts, they perform really well in some conditions, but they don't go to windward all that well.

A modern multihull of any description is about the safest platform in severe conditions that can be created. They become a huge raft. A well built Wharram should tend itself rather well, perhaps better than a lighter craft with greater windage, but having had occasion to surfed backward down waves that were too steep to motor over, I'd rather keep out of those conditions!

I think you should also recognise that the Hobart boats were racing boats. Racing Cars don't have airbags, ABS or cruise control, and are never compared to people movers, yet it's expedient to do so when boats are concerned apparently! There is a world of difference between the two.

I certainly would still seriously question the abilities of some of the more modern catamarans in this fundamental seaworthiness of windward ability and being able to survive extreme events.

No one can disagree. Some "Name" designers have produced product that won't perform as well as a Wharram either.

Lots of amateurs have jumped on the bandwagon too, calling themselves designers, and have produced caravans with almost no redeemable features. That doesn't make the boat in question perform better though.

Here is the link to Wharrams page on windage which as you know has a lot to do with windward ability-

yep. As indeed do underwater shape, foils, and sail configuration. Have you ever wondered why you never see a Wharram rig on a racing fleet?

I've never seen an Wharram dissertation on pitching either, but that's not to say he hasn't done work in that area. It's definitely unfair of me to say that some of the worst examples of hobby horsing I've encountered have been on Wharrams, because I haven't sailed a lot of really crook boats, but it is a fact.

I'm not falling into the trap of comparing cruisers with racers here, but making the point that the racers use the efficient shapes, and the efficient cruisers emulate them by and large.

The claim Wharram likes to make about his designs is that they are catamarans that are remarkably sea-worthy, secure and very unique."
And that I believe is a statement that has credibility.

No problems with any of that, but quite correctly IMHO, I don't see reference to any stupendous ability to windward, nor do I see any claims at comparitive performance.

The problem with publicity, is that's what it is PUBLICITY. It's not there to be believed. There are so many people doing Wharram better than Wharram now there's no need to hang on to the ghosts of Christmas past!

Check Bob Oram for one.

ps when can we start talking about Bolger designs?

Now you see, if Wharram knew half as much about BOAT design as Bolger, that is what makes 'em go, as opposed to what makes 'em sell, we wouldn't be having this debate!


Cheers,
P

[bitingmidge]

Or you'd see racing boats incorporating Wharram ideas.

Damn!

Have you seen the sails on the latest America's Cup boats?

THEY DON'T COUNT!



P

[mark_dugong]

G'day Biting Midge,
Ouch, ouch, ouch-guess I've been bitten by a sandfly/midge and as my sharpie is up in Sandfly Straits -I know what it is to be bitten-just don't anchor too close to those mangroves!
Yes, I will concede the Wharram cats are not that fast as catamarans these days but they do go to windward (at about 5 kts) and they will get into the 'teens going downhill and when you add their incredible ability to survive extreme conditions (like most rafts will),they become a reasonably attractive package, especially if Wharram's sales team have been able to tweak the romantic nerve which seems so overexposed in the sailing fraternity.
Thank you for your post and I look forward to more posts.
Cheers
Mark

[mark_dugong]

I know this is not part of the thread but just my way of saying hello.Attempting to attach photo of my Bolger sharpie "Dugong" at Kingfisher Bay in the Great Sandy Straits
Not an action photo but it is the only one I have
Cheers
Mark

[bitingmidge]

Nice one Mark, but what's with the sharp bow??

How do you climb up from the beach?

How about you pop down to Mooloolaba one weekend and we'll get some super sailing shots (and I might get a test drive too!)

P