About: Rick

Owner of a Catalac 8M and Catamaransite webmaster.

Posts by Rick:

Catalac 8M/9M Rigging Tune

Sailboat Rig tuning is an art rather than a science and varies from boat to boat and from low winds to high winds. Remember that the rigging on a monohull unloads as the boat heels and spills wind out of it’s sails. When you look at Catamaran rig tuning, we have to keep in mind that our rigs never unload. We have stiffer masts because of this and larger diameter wire stays. As with all sail boats, the rigging not only holds up your mast, but also has an effect on sail shape, and therefore affects performance.Racing boats have several rig tension setups depending upon wind speed the day of the race. For a cruising boat, this is impractical, and it makes more sense to aim for one rigging setup that pretty much fits all the conditions. At the same time addressing two of my particular challenges that need help. […]

Propeller Drag Under Sail Test

Propellers are a sailboat subject which sometimes turns into extremely heated exchanges when sailors gather and discuss propeller drag under sail. There are two schools of thought, of course. One school says that for best performance, propellers should be locked in reverse when sails are raised, and the engine(s) stopped. The other school of thought says that our transmissions should be put in neutral, and the propeller(s) allowed to free wheel while sailing with the engine off.  This is of particular concern for us cruising catamaran owners as we have two propellers in the water and double the drag. We all know that underwater drag under sail is drag we can do without. So, which school of thought is correct? Hint …you don’t have Helicopter rotors on a boat. I have never seen so much misinformation on a sailing subject tossed around the sailing forums as there is on propeller […]

Catamaran Design Formulas

Part 2: With permission from Terho Halme – Naval Architect While Part 1 showcased design comments from Richard Woods, this second webpage on catamaran design is from a paper on “How to dimension a sailing catamaran”, written by the Finnish boat designer, Terho Halme. I found his paper easy to follow and all the Catamaran hull design equations were in one place.  Terho was kind enough to grant permission to reproduce his work here. Below are basic equations and parameters of catamaran design, courtesy of Terho Halme. There are also a few references from ISO boat standards. The first step of catamaran design is to decide the length of the boat and her purpose. Then we’ll try to optimize other dimensions, to give her decent performance. All dimensions on this page are metric, linear dimensions are in meters (m), areas are in square meters (m2), displacement volumes in cubic meters […]

Catamaran Hull Design

Part 1: Notes from Richard Woods Since the America’s Cup experimented with going multihull, there’s been a lot of interest in catamaran performance and the catamaran hull designs that define performance. Many guys are investigating whether to buy a catamaran or design and build their dream boat. Let it be said here that building a large catamaran is not for the faint of heart. People begin building 100s of boats a year, yet few are ever completed, as life always seems to have a way of interfering with a good boat build.  Never the less, since the rest of this website is about selecting and buying a boat, it only seems fair to have at least one webpage that covers catamaran design. This page contains notes on boat hull design goals and an accompanying page from Terho Halme has mathematical formulas used in actual catamaran hull design. It has become […]

Fixing the infamous Catalac Catamaran window leaks

A dry boat interior To say that I’ve had a problem with my Catalac windows leaking would be the understatement of the year. Catalac Catamarans have had a chronic window leak problem and yes…. my boat is no exception. The leaking windows have been my pet project especially the port and starboard cabin window units. Let me tell you what I’ve done so far, and what works and what doesn’t. The first thing I did to stop the leaks was to grab a caulking gun and put a bead of latex caulk around the exterior of the offending windows… I was neat and meticulous and very proud when it was done. Until the next rainstorm that is…. the result was no effect at all. Everything still leaked as if I had done nothing at all. Very frustrating …. Next, I made sure I sat in the boat and forced myself […]

Catalac Catamaran inspection / haul out recommendations

When considering a Catalac catamaran purchase, one should always hire a boat surveyor. The list below are some things to watch for which are unique to Catalac catamarans. Surveyors should add these to their normal list of items to check. Basic Catalac Construction Catalac catamarans have: Solid fiberglass hulls End grain balsa cored decks Safety glass. No plastic windows Solid fiberglass cabin tops with 8cm end grain balsa sandwich “battens” for extra strength at hardware mounting points. These battens run fore / aft. Cable / Quadrant steering system Steel chainplates mounted inside the cabin on forward bulkhead. All cabintop hardware mounting points are reenforced with end grain balsa layers. Hauling out a Catalac Catamaran Catalac catamarans have two bulkheads, which hold the boat together. One separates the front berth from the salon and the rear bulkhead where the cockpit door is hung. Slings should be positioned as close to these […]

About Catalac Catamarans

What is it about catamarans that holds people’s attention? The America’s Cup actually went as a completely multihull event for a few years, and that got people’s attention. Then, of course, the Caribbean is literally overrun by catamarans, which has made them a popular topic in sailing circles these days. People are now including them in their boat research, and discovering cruising catamarans have as much as 50% more room than a monohull of the same boat length. What is just as interesting is they are bright and airy inside, they do not heel (lean) under sail and are incredibly stable both at anchor and under way. Catamarans do not roll at anchor, nor while sailing downwind. In other words, these boats are a lot more comfortable than a comparable sailing monohull and women love them. So why isn’t everyone sailing one? In asking around in various marinas over the years, […]

Catalac Catamaran History

Following the successful development with Bill O’Brien of the Bobcat Catamaran in the 1960s, Tom Lack Catamarans LTD specialized in building these early cruising catamarans. In fact, they built hundreds of Bobcat Catamarans. It was 1970 when they came to the decision to end building O’Brien’s Bobcat and working with boat designer John Winterbotham, created their own design, the Catalac 9M. This marked the beginning of the Catalac line of cruising catamarans.   The Catalac 9M was formally introduced in 1970, followed by the Catalac 8M in 1975, 12M and then the 10M. The boats had a stellar reputation for build quality and seaworthiness. Close to 1000 cruising catamarans were built by the Lack family, 600 of them were  Catalacs, making them a cruising catamaran success story as well as one of the pioneers in multihulls. A related footnote is that boat builder Tony Smith of Performance Cruising Inc. (Gemini Catamarans) also worked […]