Prototype Started! – pH 850 Catamaran

Prototype Started! – pH 850 Catamaran

Phillips Boatworks is thrilled to introduce the pH 850 Catamaran. Measuring 8.5 meters (28 ft) on the waterline by 5.2 meters (17 ft) wide, the pH 850 is a light and powerful recreational performer. Filling a gap between the extreme high performance grand prix and the heavier low performance production boats, the pH 850 features a unique de-mountable hard aft cockpit and just enough interior space for 38″ Twin Births, Head, and Galley. The flexibility of the design is key. It can be a winner on the race course; the venue for countless family sailing adventures; and/or even used as successful day sail charter business. With an unloaded weight of 1200 lbs, its carbon fiber pre-preg hull construction sets the pH 850 apart from all other production multi-hulls. There is nothing on the market as light, fast, fun and easily trailerable!


  • LWL – 28 feet
  • LOA – 30 feet
  • Beam Over All – 17 feet
  • Hull Beam – 39 inches
  • Waterline Ratio – 12:1
  • Mast Clearance – 48 feet
  • Draft Boards Up – 8″ Boards Down 5′
  • Mainsail Area – 302 sqft Solent 128 sqft = 430 sqft working sail area
  • Designed Lightship Weight – 1200 lbs
  • Trailer Width – 8.5′

Design that is Innovative & Simple.

The pH 850 breaks down in a few hours to trailer behind any average car at 8.5′ wide. While the interior is sparse in order to reduce weight, it is useful for light cruising and camping adventure, featuring twin births in each hull with head and galley options. The ultra-lightweight carbon twill canopy covers slide forward to create standing room in the hulls between the twin birth and chart table. When shut and locked, the canopies are water tight. When paired with a mast head float, the vessel has the potential to be righted by loosening the high side stays.


Easy to sail and designed for exciting times on the water. Optional transom steps with a water level swim platform and fresh water washdown make the pH 850 very friendly for snorkeling, swimming, and diving. Rudders for recreational sailing kick-up automatically as they touch bottom still or optional high aspect racing rudders for those more competitive intent. The hard aft center cockpit features a comfortable seat height of 12 inches before any cushions are added. In the center front of the cockpit is a multipurpose control console (plinth) that consolidates most of the rigging controls for single handed sailing. All lines are fed to the 2 primary 2 speed 40:1 self tailing winches; plus an underside nacelle for floor stiffness and the outboard engine, which also help reduce bridge deck wave pounding. In front of the rotating mast is a spacious and comfortable trampoline. Nothing beats a catamaran for its trampoline net forward space (high, dry, level, and spacious): ultimate chill and relaxation; sail storage; weight savings; reduced wind and wave resistance, and more.

Hull shape that looks good and makes sense. Starting with a fast and narrow 12:1 waterline ratio this shallow 8 inch draft hull rises first to a splash chine that serves multiple purposes. In addition to looking good, it widens the interior just enough for twin births. The splash chine helps insure a dryer ride. Also a safety feature — when pressing the boat really hard, as the hull submerges, buoyancy is increased as the chine submerges. Structurally, the chine is a longitudinal hull stiffener akin to 4 I-beams running the length of the hulls. From the Splash Chine the topsides rise up to the hull/deck chines which research shows to reduce windage on the side of the hulls. Under the canopy openings and merged into the cockpit the deck features a flush raised plateau helping to make the interface between removable cockpit and hull sides a simple flat face connection.


No Beams! – For the most part the cross beams are eliminated making the trailer and decommissioning process even more simple. When collapsed on the trailer, the inner hull flanges mate together for hull stability on the trailer while the cockpit is hoisted up and out of the way, without removing any of its components or systems.

Sailing Horsepower – The combination of the best strength:weight ratio carbon hull construction, a 45 foot carbon rig and ample sail area above the water, asymmetrical curved daggerboards and high aspect cassette rudders (as an option) this is an extremely fast and competitive multihull. The curved daggerboards in each hull generate enormous upward and windward lifting force also increasing the righting moment, the pH 850 will not only go fast, but also point extremely well upwind. The wave piercing bows and wide underwater transom section, this is a hull that will ride very smoothly though even the most aggravating choppy sea conditions. When there is no wind, the aux propulsion is stowed underneath the hard cockpit inside a nacelle shape that deflects wave chop from slapping the bridge deck, as well as very effective stiffener for the cockpit sole.


pH 850 – Versatility like no other catamaran or trimaran! Sailing/Camping adventures, regatta trophy winner, intimate charter day sailor and demountable and trailerable to destinations that are begging to be explored. The pH 850 is a great investment in fun for family and friends…. or you can make it a business and find a fun spot to offer Captained Daysail Charters.

On a personal note, my family is passionate about this design because it is exactly what we like best about sailing. In addition to sailing fast, which is always more fun, from our youngest 1 year old baby girl, who is much safer in the hard aft cockpit, to our adventurous 6 and 10 year old boys who love surfing, swimming and other watersports. We frequently keep our boats on a shallow water mooring where it only takes a few minutes to hoist the mainsail, release the mooring line and be off sailing. If you like sailing more often, this is a boat that is so convenient and simple to get underway, that squeezing in some daily sailing before or after work becomes the norm. To us, this is what its all about: keeping it close to home and accessible so we can be on the water more often.

I want one, how much ?

When prototyping and building the first couple boats, locking in pricing is one of the biggest challenges. We would love to set a price, like $120,000 for instance, as the base boat price, but to be perfectly honest, until the first boat is built and all the costs tallied up, a number like this is only a target to shoot for. In the meantime, as we build the prototype, there is a growing list of potential new pH 850 Boat Owners, and this is exciting news.

As the prototype gets near completion and more is known about the build process and cost of materials, the final price can get much more dialed in. There is also a critical number of buyers needed to meet a minimum order savings/discount with some of our suppliers. Our plan is to subcontract much of the production process to established builders capable of this type of hull construction, and they need reassurance of a minimum quantity before committing to reasonable bulk pricing.

The good news is that an enormous amount of production learning curve was overcome in the production of the Stiletto X Series. While the Stiletto X was a larger boat, it was not too much different in production style and design than the pH 850. There are differences to be sure, and this is also good news because these differences come from what we learned not to do with the previous effort. In particular:

  • pH850 is a smaller boat at 28′ LOA and 17′ Beam and 4′ deck height outside the canopy cover footprint. Unlike the Stiletto X which had to reduce from 19′ wide into trailer width via folding cockpit parts, the pH 850 does not need to do this at 17 ft wide.
  • The hull shapes are asymmetrical with part of the hard cockpit interface being part of the inner hull sides. This inner side flange creates more room inside the hulls for storage and steps to get down into the hulls
  • The interface between cockpit and hull side flanges is a simple flat face. When trailered these 4.25′ wide hulls meet for stability while the cockpit is lifted up by rigging coming down from the mast.
  • The Cockpit is engineered to be the connector between the hulls and there will be no collapsing or removable beams
  • The Canopy covers are designed to be water tight. There is some resemblance to the Stiletto 27 Canopies, but a long hard effort was made to redesign these into a more modern style and shape. The finished Canopy Covers on the pH 850 are less round and more chined. They will be made of lightweight carbon twill and honeycomb instead of heavier polycarbonate.
  • There is a transom step option for the cruising and charter oriented buyers
  • The hull has 2 chines. The lower chine is a splash rail with a pretty straight profile and the upper chine is design to help reduce windage.
  • The deck cockpit interface is a simple raised plateau, solving many of the previous shape interface issues we had on the Stiletto X
  • The underside nacelle is designed to hold the longeron and take the compression of the mast.
  • On the deck side of the mast step there is room now for a nice self tacking solent traveler.

One of the most costly mistakes in the Stiletto X Series was to not have asymmetrical molds. To add the necessary parts to the hulls once out of the mold we may have been spending up to an additional $60,000 in labor and materials to make the symmetrical inner hull sides have asymmetrical characteristics for holding the beams and cockpit together. While it will cost more initially to have 4 hull tools, the production savings will quickly outweigh this additional cost.

If you like what you see and think this is the boat for you, let’s talk! Email us at or call 252-489-8193 to find out more. Once there are a minimum of 10 owners in the queue, we will form a class association and make a build plan.

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