Gemini 105Mc Buyer's Guide, the Slip-Friendly American Catamaran

The Gemini 105MC for sale market, and why it never dries up

Type gemini 105mc for sale into a search engine and you will find more listings than for almost any other cruising catamaran under 35 feet. That is because Tony Smith's design is one of the most-built cats in American history. Cruising World reported that Gemini's total had reached 1,193 boats across all versions by the time production moved to Catalina, and the 105Mc was the last and most refined of the original Performance Cruising line.

The appeal has always been practical. A 14 ft beam fits a standard marina slip, so you avoid the catamaran surcharge most marinas apply. With the centerboards raised the boat floats in about 18 inches, which opens the Bahamas banks, the Florida Keys backcountry and the shallow corners of the Chesapeake. And the price, $60,000 to $150,000 used, puts a cruising cat within reach of buyers who would otherwise be looking at a 30 year old monohull.

From a Maryland fire to 1,000 Geminis

Tony Smith was a British multihull pioneer who built more than 270 Telstar folding trimarans in England before shipping his molds to Mayo, Maryland, in 1980 and founding Performance Cruising. A few months later a fire destroyed the factory and molds. Out of the ashes he designed the Gemini catamaran, using hull molds shipped from the UK; the first boat was named Phoenix. SAIL magazine counts some 1,000 Geminis built over the next 30 years in five versions.

The early 3000, 3200 and 3400 shared molds. In 1995 Smith drew an all-new boat, the 105M, with finer hulls and a 9 to 1 hull length to beam ratio. The 105Mc, which sailboatdata lists from 2003 to 2011, kept the hull and refined almost everything else. The Great Recession then pushed Performance Cruising into trouble; its main dealer, The Catamaran Company, bought the assets in 2009, Tony's daughter Laura Smith Hershfeld became president, and the redesigned Gemini Legacy 35 with fixed keels and twin inboards followed in 2013, built first by Hunter and later by Catalina in Largo, Florida.

What the Mc changed over the 105M

The most visible change was the cockpit, which on the 105Mc can be temporarily enclosed with canvas or solid panels, turning it into a usable extra room in cool weather. The rig grew too: the mast is a foot taller than the 105M's, and the full-batten mainsail jumped from about 260 to 340 sq ft. A 150 percent genoa adds roughly 350 sq ft, and the optional screecher of about 490 sq ft tacks to a carriage on a curved track across the bowsprit, so it can be trimmed to windward without a pole.

Reported total sail area rose to 690 sq ft on an 8,000 lb boat, giving a sail area to displacement ratio near 27.7 and a displacement to length ratio of about 112. Those are lively numbers for a cruising cat, and they explain why owners who are used to heavy charter catamarans find the Gemini surprisingly quick in light air.

Centerboards, kick-up draft and the Sillette drive leg

Instead of fixed keels the 105Mc uses two asymmetric centerboards built of fiberglass and Kevlar around closed-cell foam, raised and lowered from inside the saloon. They pivot up if you touch bottom and they let the boat point higher than a fixed-keel cat of this size. Testers reported 6.5 to 7 knots close-hauled and 7 to 12 knots once cracked off, with little heel under a reefed main and 90 percent jib in 25 to 35 knots.

Power is a single diesel on the centerline, a Westerbeke rated at 27 hp on late boats, driving a Sillette sonic drive leg that retracts out of the water when sailing. The single engine keeps costs and weight down, and the leg lifts clear for beaching or for reducing drag. Brokers commonly quote a 6.5 knot cruise and about 7.5 knots flat out. The trade-off is maneuverability: unlike a twin-engine cat, you cannot spin the boat in its own length, and close-quarters docking in a crosswind takes practice.

Tankage is modest at 36 gallons of diesel and 60 gallons of water, which is fine for coastal cruising but means jerry cans or a watermaker for longer island hopping.

A 14 foot wide saloon on a 33 foot boat

The saloon spans the full beam and has a C-shaped dinette that seats six to eight and drops into a double berth. Testers measured headroom of about 6 ft 7 in after the cockpit sole was lowered, with more than 6 ft throughout. The galley runs along the starboard side with a two-burner stove, twin sinks, a refrigerator and a built-in microwave, and a navigation station opposite has an 89 inch work surface.

The master stateroom with a queen island berth is forward amidships to starboard, the single head with shower is forward to port, and two double cabins sit aft, one in each hull. Six adults can sleep aboard, eight at a squeeze, but Tony Smith described the 105Mc as a couple's boat and that is how most owners use it. Air conditioning is a common retrofit and fits easily into the cabins.

Build quality and the issues owners talk about

The hull, deck and interior liners are solid fiberglass laid up in vinylester over a barrier coat, with half-inch balsa coring limited to the foredeck, cabintop and cockpit areas that carry no fittings. The hull-deck joint is a shoebox type bonded with polyurethane adhesive and through-fastened every five inches under a rub rail. That is a simple, robust approach, but leaks at the joint and around deck hardware do occur on older boats, so check the balsa areas with a moisture meter.

Tony Smith himself judged the 105Mc about 1,000 lb heavier than intended and lightened later boats with thinner plywood and bins instead of drawers. The bigger refit headache is wiring: the looms were tied to the liner before it was bonded to the hull, which leaves much of the wiring almost inaccessible. Any electrical upgrade, from lithium batteries to new electronics, takes planning. Centerboard pivot wear, cracked trunks and a tired Sillette leg are the other big-ticket items.

Budget ownership, and where the Gemini fits

This is one of the cheapest ways to own a cruising catamaran. Because it fits a regular slip, annual costs of roughly $9,000 to $20,000 are realistic for many owners, covering a slip, insurance, a haul-out with bottom paint, drive leg service and sails over time. The large owner community shares fixes for almost everything, and the boat's mechanical simplicity means a handy couple can do most work themselves.

Cruising World's 2026 entry-level guide summed it up well: buy the Gemini if your heart is in the shallows and your wallet has limits. It is not a bluewater passagemaker in the way a heavier, higher cat is, but for the Chesapeake, Florida, the Bahamas and island hopping in settled weather, very little does the job for less.