At a glance, the boat stands out for its towering unstayed cat-ketch rig and unusual hull form, which combines an abrupt spoon bow with a voluminous, radiused stern.
Design and Construction
Tanton drew the 45 in 1983. The hull and deck specification calls for end-grain balsa core with Nytex E-glass and isophthalic polyester resins chosen for osmosis resistance. In the deck, marine plywood replaces the balsa wherever hardware is mounted. In the hull, the balsa core is confined to the topsides, from three inches below the rub rail to six inches above the waterline.
An Airex-cored structural grid of longitudinal stringers and transverse frames stiffens the underbody. The cast-iron ballast is encapsulated in the hull, eliminating the need for keel bolts. The keel is a longish, low-aspect NACA foil, with a well-protected, skeg-hung rudder aft.
Tanton gave the boat a full, powerful stern, with volume above the waterline to provide static buoyancy in following seas. Forward, sharp sections at the waterline flare into strong deck lines. With a designed displacement near 26,000 pounds and a 35 percent ballast ratio, the boat comes across as a bantam voyager rather than a heavyweight.
Rig and Handling
Tanton maintains that the cat-ketch rig is central to the boat’s stability, performance, and ease of handling. The mainmast rises about 55 feet above the waterline, and the mizzen is almost as tall. Both are unstayed and carry highly roached, full-battened sails on either wishbone or traditional booms. The designer encourages wishbones because they don’t require vangs.
The freestanding carbon rig weighs roughly one-third as much as an equivalent stayed aluminum rig. Without conventional standing rigging, the decks also remain clear and easy to negotiate.
Owners report that the wishbone absorbs the shock of gybes so completely that turns can be made all standing in 30 to 40 knots. They also say the boat can be tacked or gybed simply by turning the wheel. One owner described the boat as perfectly balanced and reported that she would steer herself upwind for miles with only the wheel brake set. Despite her modest five-foot draft, she could still sail competitively upwind and recorded 18.6 knots while surfing down a big wave.
Cockpit and Accommodations
The large, secure cockpit is nestled into the aft deck and has a convertible table seating eight to ten. The main hatch is offset to port. At the base of the companionway is a navigator’s niche, flanked by a port quarter-berth and wet locker, with the galley beyond.
The owner’s double berth occupies the starboard hip and has its own head and stand-up shower. In the saloon, a generous U-shaped settee and large drop-leaf dinette sit to port. Built-in armchairs are arranged to starboard, behind a pilot berth.
A second head with shower is forward to port, serving both the main cabin and the double berth in the forepeak. The engine sits amidships and can be reached from all sides through convertible galley cabinetry.
Known Issues and Options
The small fleet has produced one dramatic anecdote rather than a pattern of defects. An owner reported that a Tanton 45 broke loose during a hurricane, surged through Ipswich harbor, and sank four other boats while suffering minimal damage herself.
Teak decks were a factory option rather than standard equipment. One owner considered them a major improvement.
The Verdict
The Tanton Offshore 45 is a rare, thoughtfully engineered passagemaker. Its unstayed cat-ketch rig offers remarkable self-steering and light-air manners in a compact, well-built hull. For sailors who value hands-alone handling and offshore credibility more than fleet commonality, she may reward the search. The trade-offs are a tiny used market and a specialized rig that demands an expert eye.
Pros
- Unstayed cat-ketch rig with wishbone booms allows single-handed tacking and self-steering upwind
- Clear, stay-free decks and low rig weight improve handling and balance
- ABS-approved drawings and encapsulated ballast reflect serious offshore intent
- Spacious, well-divided interior with two heads and all-around amidships engine access
Cons
- Only five hulls were built, limiting market exposure and familiarity with spares
- Five-foot draft and moderate displacement trade ultimate upwind bite for shoal capability
- Teak decks were optional, so some boats lack that owner-praised improvement
