Catalac Catamaran
Some of the arm chair sailors prowling around on the boating forums have called Catalac Catamarans a ‘dated design’ because of their hardchined hulls. You will note that catamaran hull design migrated to rounded bilge designs in the ’90s (ie… Gemini). The reason I mention this is that if you paid attention to the America’s Cup racing series last year you may have noticed that BMW Oracle uses a hard chine main hull on their boat, and they’re obviously very successful campaigning that boat.
Catamaran designer Richard Woods noted that when run through hull design software, we discover that surprisingly, the added hard chine reduces WSA, which results in less hull drag, leaving us to conclude that a hardchine hull (as used on Catalacs) is better than people think, and in addition to lower WSA, they allow greater loads to be carried.
He went on to say that Catalacs have a very clever hull design. They are hollow and deep forward and then almost flat aft. The idea being that it was so asymmetric that it wouldn’t pitch. And it would sail to windward a lot better than the old O’Brien boats (Bobcats) despite not having keels. As history has shown, with the advent of the added skegs Catalacs sail very well and are much better boats than they look, as Prouts are much worse than they look.
So, if a hardchined hull is good enough for an America’s Cup winner, it’s certainly good enough for me! Anyone want to bet that there’ll be an explosion of hard chine catamaran designs in the future??
Catalac Ancedote
Speaking of Prouts…… Prout’s place in history was cemented by folks who circumnavigated with their boats, beginning in the ’80s. As near as I can figure, one of the first men to do it was Neale Ensign who took 6 years to complete the journey in S/V Psychic Flight. He was a San Francisco Prout dealer who decided it was more fun using the boat than selling them. Neale is a very knowledgeable guy and these days happens to be a friend of mine, as when his journey was completed he picked my corner of the world to settle down.
The point of this story is that I met Neale when he wandered into my marina, approached me and tried to buy my Catalac. Not a bad thing ordinarily, except my boat wasn’t for sale. I’m not complaining as I made a new friend and got a copy of his book on the circumnavigation. It’s interesting reading.
Now consider…. if Prout people sell their boats and try and buy a Catalac, what does that tell you?
Catalac Catamaran Build Quality:
Catamaran construction techniques have evolved over time. Boats are now built with some type of coring in their hulls and decks to reduce weight (weight= material cost) and improve performance. While newer boats do perform better because of the use of coring, they have a whole set of construction issues which develop because of it.

Catalac Catamaran Build Photos
When considering a cored hull boat one must understand that any used boat which was designed and constructed with coring material has to be carefully examined before the purchase. If not properly cared for, these boats are subject to water ingress over time which unavoidably leads to the fiberglass delaminating as the layers of glass separate from the coring material. Some boat owners are meticulous with regular schedules of hardware bedding on the boat…. and others are not. Boat Broker docks are full of cored hull boats with delaminating issues, and surveyors have been known to miss it.

Catalac Catamaran construction techniques avoid this entire issue as the boats were built with double thickness solid fiberglass hulls (I tell people they are built like a battleship). Take just one look at these older boats and it’s evident they are built to last. I think you would have to look at a few older (and in some cases newer) Catamarans from different builders to really appreciate a Catalac’s build quality.
The message here is that when it comes down to comparing boats, it’s not all about speed. Unless you plan on spending $350k-$1.5 million to purchase a brand new boat, catamaran hull design and construction techniques should be your number one consideration when selecting a pre-owned Cruising Catamaran.
Catalac Catamaran Market Position:
A boat’s current value is based on condition, equipment, time since last refit, and of course the boat model’s perceived value in the marketplace. Catamarans in general have recently become very popular and the Catalac’s current value has benefited immensely by this new interest in catamarans. Here is a link to a search for Catalacs offered for sale on what is probably the most comprehensive boat marketplace, Yachtworld, as well as boats listed for sale by owner on this website. As Catalacs are a British built boat, it’s not surprising that many of these boats are in Europe.

Consider that over 98% of the 600 boats produced are still sailing today (2015), yet only a handful of most models are typically offered for sale. Overall, Catalac owners are very pleased with the build quality and satisfied with performance. However I think the real reason most folks hang onto their Catalacs is that they are unable to discover a clear upgrade path. Consider that there are no catamarans available approaching Catalac build quality, which are 2 or 3 meters longer, and which are offered for a reasonable price. In addition, as you can see in the individual boat model charts (select in the menu bar), very few Catalac Catamarans were sailed or shipped to the Americas. This has resulted in increasing Catalac boat prices in America despite what has become a depressed boat sales market. A truly remarkable phenomenon which reflects the increasing popularity of catamarans in general, as well as the lack of affordable boats in reasonable condition offered for sale.
Catalac Boat Pricing explained:
When researching these boats you may discover that the Catalac 8M and 9M have a somewhat wide range in pricing. This requires an explanation. Tom Lack offered several engine powering options on the smaller Catalac models. Boats built with the OEM outboard gasoline/petrol engine are much less expensive than those which were built as pocket Cruising Catamarans with twin diesel engines with shaft driven props.

Catalac Catamaran Innovation:
Have a look at the construction photos. You’ll notice that the cabin, cockpit and bridge deck are one piece, an early innovation which is the strength of these boats. The hulls are solid glass and only the foredeck is balsa cored. The boats have two 3/4 inch hardwood plywood bulkheads installed which tie the hulls together, and then the cabin/deck/cockpit (another one piece mould) is installed to complete the assembly.
Catalac Rigging:
With Catamarans, there has always been a concern over tightening the stays. Over tighten Port and Starboard lower and upper stays and in time your boat’s two hulls begin to pull up, bending the boat in the center. Tom Lack came up with a solid method of preventing this as the boat is rigged using the forward bulkhead. The chainplates pass through the roof and are anchored to 1/4″ metal plates which are in turn anchored solidly into the forward bulkhead. You can see the chain plate brackets in the interior photos in the brochures provided in each individual boat page. When tightening rigging stays, tension is applied only to these bulkheads and never to the hulls. In my opinion, this is an additional terrific design benefit. Over tightening rigging can never warp a hull on a Catalac.
Diesel Engines in catamarans:
People who automatically dismiss the concept of twin diesels in a catamaran are people who haven’t sailed in one. Safety, redundancy, reliability, maneuverability (especially with high winds on the beam when docking), speed, battery charging capacity and cruising range, are all greatly increased with twin diesels and are well worth the additional investment. Outboards have cavitation issues, and just how do you keep them in the water when it’s blowing 60 knots and you’re in short period waves?

Also, consider that diesel engines can run for 10,000 to 15,000 hours before a rebuild and a gasoline outboard for 2500 to 3000 hours if you’re lucky. In the long run, the cost differential is not as great as it would appear to be, especially if you repower with rebuilt diesels. If you plan on actually sailing your boat and it isn’t destined to become a ‘Dock Queen’, I definitely recommend twin diesels in any catamaran you might consider.
1 reply on “Catalac Catamarans Design Review”
Hi Rick great tnfo I have an 8.3 mtr she has 2 fully restored yanmar 10hp she is the best boat I’ve ever had I can ho anywhere in her cheers Paul jewell