The Ultimate 18 was designed by Gerry Fletcher and constructed by John and Harry Twiner of Ultimate Yachts Pty Ltd (located at Unit 2, Bray Court, New Street, Frankston, Victoria). The Ultimate 18 is a rugged, fibreglass drop-keel family trailerable yacht (Hopkins, 1975, p. 40). It was designed in the early 1970s, during the formative years of retractable keel yacht design. At that time, Gerry Fletcher, a seasoned designer with over three decades of experience, crafted a small wooden family yacht tailored to a specific vision. His goal was to create a safe, seaworthy boat that was spacious enough for comfortable overnight stays while remaining competitive for class racing, a philosophy that defined the production fibreglass models (Ultimate Yacht Association, n. d.).
The Ultimate 18 features a spacious cockpit, with a wide mainsheet traveller separating the aft helm station from the rest of the crew, complemented by well-placed non-skid surfaces. Inside, the heavy retractable keel housing splits a cabin that accommodates at least four adults for sleeping, with a galley on the starboard side. With a displacement of 680.4 kg (1,500 lb) and 204 kg (450 lb) of ballast, it maintains a 30% ballast ratio: the recognized threshold for self-righting capability. It is also noted for being straightforward to launch and retrieve, with a mast that is easily raised and sails that furl neatly (Hopkins, 1975, p. 40).
A swing keel variant was also produced; though rarer, these models still appear on the market. The initial swing keel version featured a straight plate, of which only about three were built. The subsequent and final iteration utilized a cast keel equipped with a small bulb (Trailer Sailer Place, 2016).
Interior headroom is significantly enhanced by a pop-top feature found on some models, and the cabin layout itself can vary. [Its maximum headroom is typically around 4 feet 9 inches to 5 feet (about 1.4m to 1.5m) with the pop-top raising this by several inches.] While a keel lockdown mechanism was fitted to certain boats, it can also be retrofitted to those without it. Additionally, while most boats feature the mainsheet traveller in the cockpit, some have been custom modified. Potential owners should note that hull weights vary depending on the amount of fibreglass applied via the chopper gun during manufacturing. Real-world weighbridge data highlights this variance: one total towing setup, including a tandem trailer and a substantial amount of gear, registered at 1,600 kg, while another unladen setup weighed 1,380 kg with no gear (Trailer Sailer Place, 2016).
“Sailing qualities of the Ultimate 18 are quite impressive. She is obviously a fast little yacht, while her fine entry and overlapping genoa give her excellent pointing ability. On the day I tested her she suffered from the lack of boom vang and cunningham eye to flatten the mainsail when the wind freshened. She had a lot of weather helm in the gusts up to 15 knots. An adjustable backstay would be an acquisition and a boom vang a must. Nevertheless, she showed lots of speed and on a broad reach we clearly outpaced a popular 27ft cruising sloop. Later, the boat gave proof of her handling and close windward ability when I sailed her hard on the wind up the fairway at St Kilda marina, tacking a dozen or more times in the narrow channel. Well tuned and well crewed, the Ultimate 18 obviously has potential for round-the-buoys racing or JOG sailing with an experienced crew. Her rating is 14.5ft, giving her a TCF of .5504″ (Modern Boating, n.d.).
Ultimately, the Ultimate 18 remains a well-supported design that behaves like a true small keel yacht on the water.
SPECIFICATIONS
LOA: 5.54 m (18 ft 2¼ in.).
LWL: 5 m (16 ft 5¼ in.).
Beam: 2.12 m (6 ft 11-3/8 in.).
Max draft: 1.19 m (3 ft 11 in.).
Keel up: .31 m (12 in.).
Ballast: 204 kg (450 lb). [204kg of lead in the shoe of the drop keel.]
Displacement: 680.4 kg (1500 lb).
Working sail area: 14.49 m² (156 sq ft).
Spinnaker: 18.58 m² (200 sq ft).
Outboard on Transom Bracket. [Verify that the rudder does not interfere with the outboard propeller during use, particularly if a high-thrust propeller is installed.]
Original Price: $5,000 plus trailer and outboard.
Sources:
Hopkins, Paul, Australian Seacraft, February 1975, p. 40.
Modern Boating,n.d. https://www.johncrawfordmarine.com.au/advice/trailer-sailer/ultimate-18
Trailer Sailer Place, 2016. ‘Ultimate 18 Characteristics and Issues to Look For’, Trailer Sailer Place, 29 August, viewed 18 May 2026, https://www.trailersailerplace.com.au/phpBB3/viewtopic. php? t=14113
Ultimate Yacht Association, n.d., About, Google Sites, viewed 18 May 2026. https://sites.google.com/view/ultimateyachtassociation/about.
Historical photograph reproduced for identification and historical research purposes. Copyright remains with the original rights holder.
Quick tip: Keep in mind that trailer sailers can vary quite a bit, even within the same class. Take the RL28, for example: they might not all have outboard wells as designed. Some originally may have had inboard engines, and when those were removed, the owners swapped them for a standard outboard mounted on the stern.
