American yachtsman Paul Tullos came across Terrorist lying on a trailer in derelict condition at the back of a local yard in 2010, looking as if she was loaded up ready for the final voyage to landfill. Tullos spent much of the next two years restoring her to better-than-new, adding a carbon mast from Goetz and relaunching her in 2014. The twin bilge boards are sadly now fixed in the lowered position, but their scale is easily appreciated, as is the absence of a keel. The ballast remains internal and the sailplan close to original – a reminder of what an IOR No1 genoa looked like in those days. In spite of that wide beam – 3.9m on a length of 10.8m – with a light displacement of just 4,765kg Terrorist was surprisingly fast in light air, dominating the light first race of the 1974 One Ton Cup. Had she not later dismasted she’d probably have beaten the Peterson design Gumboots to the One Ton Cup. If…
The still new rule created many unfore-
seen opportunities for new designers as yet untainted by the conventions of ‘what a proper offshore racing boat’ should look like. And sure enough, for example, only a mere three years after the rule was launched, a certain Doug Peterson came along, with a relatively small and light One Tonner called Ganbare that quite literally changed the direction of yacht design. But unlike the rulemakers’ penalising
response to bilgeboards, and other radical innovations, the new shape introduced to the offshore scene by Doug Peterson and Ron Holland, as well as the extreme beam and ultra-light displacement on Quarter Tonners like Robber in 1973, did not prompt authorities to introduce knee-jerk rule changes that aimed to control design direction. Such were the opportunities – some would call them loopholes – offered by the IOR that this mixture of desirable and undesirable developments manifested itself in many ways. But the rulemakers still found themselves simultaneously deal- ing with an assault on their embryonic rule from a range of other different directions. The cat-rigged ketch Cascade, for
example, took a finger on the throat approach to the norm that was, arguably, even more left field than the bilgeboarders. Professor Jerry Milgram, of the Massachu- setts Institute of Technology, had spotted a king-sized loophole in how sail area was measured, exploiting it to the max with a sailplan devoid of headsails. The idiosyn- crasies of the nascent rule were such that so much unrated sail area was unleashed that Milgram was able to design a 30ft waterline boat that rated as a Half Tonner – a size of boat normally limited to a waterline length around 23ft! But despite the rating penalty dished out
to Terrorist, Bruce King did persuade three more owners to have developments of the concept – Hawkeye at 48ft and a couple of Two Ton sisterships, Aggressive II and Popeye. Both designs followed the Terrorist template of light displacement, lots of beam and big tumblehome (to help with large angle stability) plus transom-hung rudders and a short overall length for the respective ratings. Another feature these
boats shared, which would be familiar to today’s designers, was the placement of the rig set nearly amidships fore and aft Terrorist and her larger sisters all fea-
tured asymmetric bilgeboards angled out- wards at 12° so that at the optimum heel angle for the boat, 12°, the leeward board would be upright giving maximum depth and lift. To further enhance the overall reduction of leeway the boards were ‘toed in’ by 3° to the centreline. A full 25-30 years before the same concept was trialled in Imoca 60s and the fearsome Volvo 70s. Terrorist’s boards could be lifted inde-
pendently or linked by a system that lifted the weather foil while the leeward foil stayed deep in undisturbed water; com- bined with the slight angle to the centreline the boards created tremendous lift to weather. Offwind both foils were retracted to reduce drag and wetted surface. The asymmetric shape of the boards not
only gave these designs extraordinary per- formance upwind, but also reaching speed where high leeway angles were typical for more conventional yachts. The higher lift of the asymmetric board allowed the boat to sail lower, with sheets more eased, while making the same course. This also helped reduce the angle of attack of the entire hull, further reducing resistance. The big Achilles’ heel, and there has to
be one, which applied to the majority of ‘keel-less’ yachts, was downwind in heavy weather. The high centre of gravity, with all of the ballast in the hull, created a tendency for extreme rolling which could be very difficult to control. I think it’s fair to say that Bruce King
didn’t fully exploit the IOR with any of his four bilgeboard designs. The short aft overhang with a transom-hung rudder was certainly not optimal in rating versus speed terms. A second-generation Terrorist would have been a very interesting boat indeed – perhaps with a Bruce Farr-style flat, full stern and a big fractional rig. But so struck were they by the clear
advantages of asymmetric bilgeboards that the rulemakers decided to slap on two additional moveable appendage penalties. This pushed the rating up even more. In reality, however, such was the potential
advantage of bilgeboards that it would have remained possible to race effectively even with a higher rating. Notwithstanding the favourable science, in truth I think that owners and designers were put off building more bilgeboarders by the perceived ‘direc- tion-of-travel’ of the IOR and its masters. Fast forward to 2025 and bilgeboards
are still highly effective in terms of boat speed versus rating under IRC, but you try persuading any owners to go that way! Certainly, back in the 1970s and even today it still surprises me that more bilge- board designs have not been created. Not only was Terrorist highly innovative
in the use of bilgeboards, but she showed the way towards a significantly lighter- displacement approach to the IOR Rule. However, this lightness, together with internal ballast and little or no ballast in the keel, wasn’t fully exploited in One Ton- sized boats for another three years, at which point a new wave of brilliant designers, including Bruce Farr, Laurie Davidson and Paul Whiting, unleashed the light-displace- ment, unballasted daggerboard concept. This latest spectacular and exciting devel-
opment swept through the IOR level rating fleets in the brief period 1977-1978… before the rating authorities flexed their muscles again in 1979 to bring the ‘centre- boarder movement’ to an abrupt halt. But, significantly, before this in 1976,
another designer, known for his radical approach to the IOR, produced a dagger- board One Tonner called Resolute Salmon. Her architect, Britton Chance, did not
follow the path set by Terrorist, but instead he became the first designer to successfully marry an unballasted daggerboard with a medium-displacement hull form that fully exploited the idiosyncrasies of the IOR. Resolute Salmonwas similar to the Peterson and Holland boats of the time, in terms of hull shape, but with an unballasted (100kg) daggerboard rather than fixed- ballast keel. Like Terrorist, two years earlier, this
new combination of hull form and keel proved equally devastating in perfor- mance/rating terms. Resolute Salmon won the One Ton Cup that year to unleash the brief era of the daggerboarders…
SEAHORSE 47
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