J/105By Jack Hornor
Revised by BoatUS editors in October 2012
The J/105 is another example of J-Boats' proven philosophy that simple, well conceived, and solidly constructed boats will succeed. After producing more than 680 boats since 1991, this remains one of the company's most popular models.
Following the J/105's introduction in late 1991, Sailing World magazine (January 2004) chose it as its "Boat of the Year" in the Racer/Cruiser category, although with 5' 5" inches of headroom in the main cabin and rather limited accommodations, I don't think this boat fits any reasonable person's definition of a 34-foot cruiser. It's not strictly a racer either, because it clearly has appeal beyond the race course, and "'daysailer" is much too narrow of definition. So, what do we call this unique model? Let's just say this is a multiple-purpose "fun boat" that will appeal to sailors who place more importance on competitive one-design racing and responsive performance than entertaining or cruising on weekends.
The J/105 measures 34' 6" (10.5 meters) length overall and waterline length is 29' 5". Maximum beam is an even 11', standard draft is 6' 6" and the designed displacement is 7,750 lbs with a 44% ballast-to-displacement ratio. A shoal draft model offers 5' 6" draft and a slightly higher ballast to account for the raised center of gravity. The majority of J/105s built are of the deep draft variety.
Tillotson Pearson International (TPI) builds the J/105 utilizing the patented SCRIMP process. Simply put, fiberglass materials and core materials are laid up without any resin. The lay-up is then sealed in plastic and a vacuum applied to remove all the air. Resin is then introduced and the vacuum draws the resin through the composite. The process allows precise control over resin to fiberglass ratios and results in a strong yet lightweight hull. TPI pioneered resin infused composites and J/105s are sold with a 10-year hull warranty that includes osmotic blistering.
The deck layout of the J/105 is very clean, yet another benefit of a simple design. There is a 20" square forward hatch which, if not already modified, will need a means to prevent the hatch from opening past 180 degrees which causes the frame to crack. The T-shaped cockpit is very large and separated by the mainsheet traveler which is within easy reach of the helm. Standard equipment is a tiller with a Spinlock hiking stick, although a 42-inch Edson wheel is offered as an option. The reversed transom has a molded cavity and swim ladder for easy boarding.
The cabin accommodations are spartan yet functional and easily maintained. There is a seven-foot-long V-berth forward by a port head and starboard hanging locker. Aft of the main bulkhead there is a small galley to starboard and navigation table to port followed by port and starboard 6' 6"-long settee/berths. The icebox is a 54-quart portable cooler that fits beneath the companionway steps.
Auxiliary power is provided by a 20-hp inboard Yanmar diesel and a Martec folding propeller.
For a boat with a sail area-to-displacement ratio of 24, the J/105 is remarkably easy to sail, even shorthanded. In fact, the only complaint I have heard about the sailing characteristics of the J/105 is her performance to windward in light air. Some have added an overlapping genoa to help in this regard, but these are not allowed by one-design racing rules which limit the sail inventory to a mainsail, non-overlapping jib and an asymmetrical spinnaker.
Once the wind picks up to over 8 knots this boat shines on all points of sail, and by all reports, is downright exciting reaching and running in moderate to heavy air. Sustained speeds of 12 to 13 knots broad reaching in 20 knots of wind are not uncommon and the well-balanced hull form, low center of gravity and large rudder allow the boat to be sailed under control in these conditions. Gone are the days of white-knuckle downwind runs and death rolls.
While I think the J/105 could be a great daysailer, her strength clearly lies in her appeal as a one-design racer. There is a very strong class association and J/105 fleets are now in nearly all major sailing centers across the country. For big boat racing enthusiasts, it's hard to beat a boat that offers great competition with a crew of two to six people when it may take eight to 10 people to crew a comparably sized handicapped racer.
Naval architect Jack Hornor was the principal surveyor and designer for Marine Survey & Design, Co., based in Annapolis, MD. He was on the boards of the American Boat and Yacht Council, the National Association of Marine Surveyors, and the Society of Boat and Yacht Designers. He and his wife sailed their Catalina 42, Legacy, based on Maryland's Eastern Shore.