1.43 The 5-Oh

Coronet, the boat that led to one of the world’s great dinghy classes. Coronet carried a large rig, with 16.3sq m (175sq ft) of working sail and a big 18.6sq m (200sq ft) spinnaker.and was often forced to carry an I-14 mainsail and the smaller of her two jibs. There’s often been discussion in the 505s about whether moving the forestay aft (to allow for a spinnaker chute) harms the jib’s efficiency, so it’s interesting to see that Coronet’s larger jib was set from the stem and her smaller jib was originally set 61cm (2ft) back from the bow.

Despite the Flying Dutchman’s selection as the new International two-man dinghy, there were lingering doubts about whether its long, flat shape could handle offshore waves. The IYRU labelled it as an inshore class, and the next year they ran another set of trials at La Baule in France to select a new two-man class for open water sailing.

Once again, the trials attracted a healthy fleet of prototypes and existing classes. Four Canetons and some Caneton developments represented the French. Two FDs represented the Dutch. The British came along with the conventional and overcanvassed but fast 17ft Marianne (designed by Claude Nethercott of Canoe fame), the Osprey, Hornet, the International 14s Thunderbolt and Fleetwing, and Uffa Fox himself on the Jollyboat. An Italian National 18 Footer, carrying two men instead of the normal three and smaller sails, came along as a yardstick. The two FDs in the event ran second and third, proved their seaworthiness, and the “inshore” restriction was removed from the class. But while the FD cemented its international place, the sensation of the contest was a boat called Coronet – the forerunner of the class that remains one of the world’s greatest dinghies.

Coronet was designed by John Westell, a yachting journalist and International 14 designer. Westell was one of those who had input into the FD design, and he sailed the boat while reporting on the first set of trials for Yachts and Yachting magazine. But like many UK sailors, he was a fan of shorter boats and believed that the FD was too stable, long and flat to give the real dinghy “feel”. When the second trials were announced, he decided to create a boat that could appeal to both European fans of long boats, and British fans of small dinghies.

Westell kept the overall length of his new design down to 5.5m (18ft), the shortest length that he felt the Europeans would accept. Instead of trying to create the longest practical waterline, as most designers would do, Westell drew overhangs on the bow and stern to keep the waterline down to 4.7m (15ft 6in) so that “in drifting conditions, the wetted area would be low and permit good speed without an enormous spread of sail.”[1]

Westell’s design was not just lighter, shorter and potentially cheaper than the FD. She was also a different concept. While the FD melded contemporary European and British ideas, the Coronet looked to the future; “convention had been spurned in pursuit of speed and nothing had been allowed to stand in its way” noted Yachting World magazine.  Where the FD was designed for cruisers as well as experts, the Coronet was aimed directly at the ever-increasing ranks of expert sailors spawned by the dinghy boom; “the gap between the top notch crew and the good-but-not-quite-the-best crew is apt to be very marked indeed in this boat” he noted at the time.

Westell also kept the future and the dinghy boom in mind when he drew the 505’s deck layout. He realized that the growth in dinghy sailing meant that rescue facilities were becoming inadequate. At a time when some “senior” classes purposely penalized capsizes by restricting buoyancy, he gave the new design unusually large tanks and transom flaps so she could be righted quickly easily.  While the FD initially used the Tornado sailplan, Westell drew a big and advanced rig with a long spinnaker pole, a complex rotating mast and deep section boom.

Westell’s design also took a leap into the future with its distinctive flared gunwales. Flares were making news in dinghy design around this time. Designers like Uffa Fox and Proctor had always objected to wide gunwales on the grounds of windage and drag. Then in 1948, Canadian I-14 sailor Paul MacLaughlin borrowed the old Uffa Fox 14 “Joyful” for the Prince of Wales Cup and “found that her bow wave threatened to swamp her when it was blowing hard”. MacLaughlin got around the problem by fitting “a pair of what looked like cherub’s wings sprouting from either bow, just below the gunwale; they were about 6 in. wide at the stem and tapered off to about 1’, 2ft from the bow. They were made of plywood and appeared rather flimsy”.

MacLaughlin’s “spray deflectors” were a classic piece of improvisation, and when he performed well people started thinking. Ian Proctor “grudgingly” put wide gunwale strips on 14s after 1952 (he was, he admitted later, wrong to be so reluctant) and in 1953, the innovative Austin Farrar launched the International 14 “Thunderbolt”. She reversed the long trend towards narrow beam by featuring widely-flared gunwales that made her 43cm (17in) wider than her near-sisters. In theory, the flare would keep the boat drier and make hiking easier and more effective. In practice, it didn’t quite work out that way. The leeward flare scooped green water over the leeward rail and into the open cockpit, the windward flare caused windage, and the extra stability tore gear apart. Although Thunderbolt now seems to be an ancestor of all the winged and flared hulls we see in so many classes, in her day she attracted as much criticism as praise.

Thunderbolt, the International 14 that inspired the 505’s flare.

I interviewed Farrar before shortly before he died in 2004, aged 91. Sadly, his memory for his many innovations had faded. He could not recall whether Westell was inspired by Thunderbolt or whether he was just working along parallel lines, but (given the timing and the publicity Thunderbolt attracted), it seemed probable that the 505’s flare was partly inspired by Thunderbolt. (NOTE – since this was written, historian/journalist David Henshall has confirmed that Westell was inspired by Thunderbolt’s flare and given permission to adopt it). But wherever the idea for Coronet’s flare came from, Westell was quite explicit about the reasoning behind the feature; “the deck was built out horizontally beyond the topsides to give an extreme beam of a little more than 6 ft, this giving the crew a long righting lever on a slim hull” he wrote.  The power of the flare allowed Westell to keep the Coronet’s waterline beam down a slender 4ft without destroying her ability to carry sail.

Coronet’s flare was flat-bottomed and angular, lacking the graceful curves of Westell’s later designs.  Some of the first published plans show the reason – under each gunwale was a “hiking seat” which would pivot out to give extra leverage when needed, or swivel back 90 degrees and sit under the flared section when not in use. By the time the trials arrived, the hiking seats had been discarded in favour of the trapeze but the thin flares, reminiscent of the 49er’s solid wings, remained.

A sketch of the Coronet’s sections. From the small-scale fuzzy plans available it appears to have slightly more Veed sections than the 505, but the main difference lies in the flat-bottomed wing-like flare sections. The plans also indicate that the earlier concept included a hiking seat that rotated out from under the flares.

Westell took another step into the future when he drew the Coronet’s lower hull sections. The turn of the bilge was hard by the standards of the day. Then, as the sections reached the waterline and flowed inboard, they gradually straightened out. From BMAX aft, there was a hint of a flat section along the keel line, instead of the distinct Vee that contemporary designs showed along the keel.  The Coronet’s hull did not have the distinctive flat of many modern designs – just a region where the gentle curves of the hull sections arced towards the horizontal (with a minimum deadrise of about 4 degrees), and the keel line almost faded away – but the semi-elliptical sections that Westell drew reduced wetted surface and increased planing lift. It’s a shape that is seen on most modern performance boats, but when Coronet was designed it was almost unknown.  Every earlier dinghy that I can find (apart from scows and sharpies) had a distinct vee section along the keel line; probably a legacy of the limitations of wooden construction, or maybe just an example of designers following an unconscious tradition. There had been a gradual movement towards flatter keel sections in some classes like Int 14s, but even the best 14 of the day (Farrar’s “Windsprite” design, the basis for “Thunderbolt”) still had a deadrise of about 15 degrees. Even the FD, which generally has flatter sections than Coronet, carried more Vee along the keel line than Westell’s design.

Free of the length and mid-beam restrictions of the Int 14 rules, Westell was able to give the Coronet a longer, finer bow with a half angle of around 15 degrees, compared to the 20 degrees of Int 14s of the time. The widest point also moved back lightly, to about 65% aft, in another step towards modern shapes.

It’s been said that Westell gave the Coronet the same stern shape that he’d developed in the 14s. In plan, the stern shows few surprises; just a long run into a transom about three-quarters as wide as the maximum beam. It was a conservative exit by more modern standards, and not too dissimilar to that of a boat like Windsprite, but Coronet’s extra length allowed the buttock lines to be drawn out to a gentler, faster slope. But there was nothing traditional about the rest of the Coronet’s rocker.  Where other boats of her time, like Int 14s and the FD, had deep bows and long flat sterns, Westell’s design had a shallower bow and more curve in the buttocks. This was no accident; “when planing started the rockered keel caused a long length of bow to lift, so once again reducing wetted area and skin friction” Westell wrote.

The trials at La Baule proved that Coronet’s performance was as advanced as her design.  She was almost as fast as the two FDs upwind, and ran away from them on the square runs. The three boats dominated the trials and raced closely together.  Although history sometimes records the trials as a crushing victory for Coronet, the facts disagree. By Westell’s own reckoning, allowing for issues like retirements, Coronet was a mere 69 seconds faster than the best of the FDs in nine hours of racing. “Had speed been the sole consideration” he wrote, “the (selection) Committee would probably not have felt that Coronet’s margin over the Flying Dutchman was great enough to justify recommending another new class.”

Coronet’s obvious quality attracted the members of France’s “Caneton” development class. Seven Canetons and Caneton developments had turned up for the trials. Some had done well, but none of them were in the same class as the FD and Coronet. Like Westell himself, the Caneton sailors came from development backgrounds but were looking to the one design concept as a cure to obsolescence and rising costs, so they asked Westell to modify the Coronet into a one design that would fit within the Caneton class dimensions. Westell was only too happy; “They felt, and I entirely agreed, that 16 ft 6 in (5.05m) was quite long enough for a two-person dinghy” he wrote. “The performance could be at least as good, if not better, than that of a longer boat, while the price must be lower and the general convenience both in and out of the water would be far better”. And so was born the International 505, a boat that many still regard as one of the ultimate racing dinghies.

As many designers have found out to their cost, scaling a design down can turn a brilliant boat into a mediocre one, but the fact that Coronet had been designed with a short waterline length made Westell’s job a comparatively easy one.  “Without altering the underwater body of Coronet, I snubbed the bow back 6 in. and lopped 12 in. from the after overhang” he noted.  He cut the weight down to match the shorter hull by “flaring the topsides out in a curve instead of building the deck out horizontally”, replacing the Coronet’s right-angled flare with the elegant curves that are a trademark of the 505. The 505 shape may not be quite as efficient as the Coronet’s angular shape, because waves can strike the flared-out sections up high, adding drag and cutting speed. Ian Proctor was probably right when he wrote that the 505’s curved flare was less effective in reducing drag and spray than the Coronet’s straighter sections, but the curves made the 505 easier and lighter to build in the technology of the day. Modern designers, freed from structural problems by superior technology, have been able to return to the Coronet style of slab-sided hulls and angular flare or wings. But the Five-Oh’s midsections still inspire modern designers. “If the mid section looks like anything it is a 505 taken to another level” is the way boatbuilder Steve Clark describes the Vanguard Vector, a production skiff type of the ‘90s.

Coronet had used her smaller sails for most of the trials, so it must have been an easy decision to discard the wingmast and reduce the sail area when Westell created the 505. “The lower displacement allowed sail area to be reduced to 150 sq. ft. without any loss of performance” he was to write.  In another look to the future, Westell retained the big spinnaker which set from a pole that was (for the time) extremely long at 2.5m (8ft3in). The 505 was perhaps the first boat that really showed the northern hemisphere the potentia of big spinnakers and long poles. As Westell himself wrote, the long pole held the spinnaker more securely in strong winds, and as early as 1955 he wrote that tacking downwind, at up to 20 degrees from dead downwind, was the norm in 505s (there is proof, incidentally, that it was popular in ocean racers as early as the ’30s). Initially, the 505’s sailplan was quite open in design and even allowed rotating masts if they were included in the measured area, but in a tribute to the success of Westell’s design almost everyone followed his plan and the class moved to a one design rig.

The 505 proved to be one of the few boats that could be reduced in size without being reduced in quality. “In fact, when they later raced together, Coronet was handsomely beaten by the Five-O-Five” wrote Westell…..”She relies for her speed in all wind conditions neither on excessive length nor excessive sail area but on a careful proportioning of everything”. The new class enjoyed the initial boost of adoption by the strong Caneton class (under the name Caneton Rapide) but it very quickly earned International status and outgrew its parent in both reputation and popularity. Paul Elvstrom never left any doubt that he thought the 505 was one of the best boats afloat, and even today top sailors feel the same.  As former world class president Ali Meller notes, “whoever developed the class rules had the wisdom to allow any material to be used in construction, and to allow some development in foils, rigs and control systems. The result was a magical boat that was far ahead of its time in 1954 but continued to develop without obsolescing existing boats.”

“It has everything” says Chris Nicholson, multiple world champ in 505s and 49ers.  “You require a fairly big crew, so that caters for big people, and the small people can steer the boats. It’s a fairly demanding class, it powers up easily enough in light air, and one thing that helps it out so much is all the controls on the rig and centerboard to help it go up and down through the range. At risk of sounding biased, I think it’s one of the best boats I’ve ever sailed on”.




[1] Seacraft, October 1957, p 52

Author: cthom249

A former sailing journalist and magazine editor, I was lucky enough to grow up in Sydney, one of the world's sailing hotspots and to win national and state championships in classes like J/24s, Windsurfer One Designs, offshore racers, Laser Radial open, Windsurfer OD Masters, Raceboard Masters and Laser Radial Masters, to get into the placings in a few other classes, and do a few Sydney to Hobarts.

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