6 November 2013

Inca (S&S 46)

Inca started life under the name of her sponsor, Marac - a yacht that was planned by co-owners Evan Julian and Don Winstone to achieve a place in the New Zealand team for the 1981 Admiral's Cup. Marac was the work of Sparkman & Stephens designer Bill Langan, who had worked on the lines of the 46 footers Obsession (US) and Lou Abrahams' Challenge (Australia). At the time Langan was considered to be leading the S&S office back into competitive design with his new generation boats, and Challenge had very nearly won the 1980 Sydney-Hobart race (narrowly losing to Ceramco New Zealand), but went on to win the 1983 edition of that great race.

Marac was built at Ocean Racing Yachts in a Klegecell, Kevlar and S-glass layup, with hull lines that were little different to the earlier Challenge, but was slightly fuller in the bow and smoother aft, providing a hydrodynamically superior shape while also rating 0.5ft lower. Julian felt that the larger size of Marac (at 46ft)  would be advantageous, compared to the minimum-rating yachts that were lining up to contest the trials, and would allow Marac to break away from the pack in the narrow confines of the Solent.  

A profile view of Challenge on which Marac was based
Marac being rushed along at Ocean Racing Yachts
Launching day
Research had also suggested that a bigger yacht, with a comparatively large sail plan, would be optimum for the Admiral's Cup, and that a boat within a rating band of 33.5-34.5ft IOR would be ideal. Marac was designed with a reasonably large fractional rig and rated at the top of this band at 34.5ft, and further optimisation was carried out to reduce this to 34.4ft for the trials.

Another decision that was taken to optimise the design for Solent conditions was to reduce the yacht's draft. Langan described this as being mostly to do with the Solent tide; "if you're beating up against it you've got to be able to get as close inshore as possible and evey inch of draft you can save is valuable". The reduction in draft, by approximately 4 inches, also conferred a slight rating advantage. The area lost in the keel went into the rudder to maintain lateral resistance.

In the initial observation trials ahead of the New Zealand trials proper, Marac showed that she could get to the finish line first against a fleet comprised of Swuzzlebubble III, Spritzer, Feltex Roperunner and Epiglass New Zealand, but needed to put roughly 3 minutes per hour on the smaller boats to hold her place on corrected time. She was joined by Ngaruru from Wellington for the trials, a sistership to Challenge but which proved to not be competitive in the 1981 fleet.
A bigger rudder did not always mean it ws plain sailing for Marac in the New Zealand trials series, seen here battling to stay on track on a tight spinnaker reach
Marac sails down past the Auckland waterfront ahead of the bunch of smaller boats
Cockpit detail
Marac went on to fight a lone battle for her place in the New Zealand team, with the bigger Outward Bound, Digby Taylor's 51ft Whitbread contender, always too far ahead to be a sparring partner. Her final corrected time record in the series was 2/2/1/4/3=/3, showing great consistency for her third overall placing. She was well sailed by Ray Haslar and Chris Bouzaid, both helmsmen in New Zealand's 1975 Admiral's Cup team aboard Barnacle Bill and Julian's original Inca respectively. Certainly Marac had the advantage of always sailing in clear air which may have helped her overall results. 

Marac powers upwind into the Motuihe Channel during the 1981 New Zealand Admiral's Cup trials
Langan was in Auckland for part of the trials and recommended ways of reducing Marac's rating further without sacrificing sail area - this was done after the trials and her rating came down another 0.2ft, which was equivalent to about 10 seconds per hour. 
Inca working up prior to the 1981 Admiral's Cup

Inca (left) drifts to the finish in the first race of the 1981 Admiral's Cup trials, just ahead of the smaller Stars & Stripes (US) and Red Rock III (Belgium)
So Marac joined Swuzzlebubble III and Wee Willie Winkie in the New Zealand Admiral's Cup team - like Wee Willie Winkie (the ex-Epiglass New Zealand), Rule 26 at the time prohibited names featuring their sponsors and so Marac became Inca. Unfortunately, Inca failed to live up to expectations during the Cup itself, becoming the weak link in the team and finishing 42nd in the individual standings (of 48 boats), with a best placing of 22nd in the second race. 

Inca sets off on the first downwind leg of the second race of the 1981 Admiral's Cup, just ahead of Holland's Caiman
Although Swuzzlebubble III performed with distinction, placing first yacht overall, Wee Willie Winkie was mid-fleet (26th), and so Inca's performance saw the team drop to a disappointing sixth overall.
Inca sailing in 1982
Inca was later sold in the UK, and later to an Australian yachtsman. It has been reported by crew from that period that the yacht did not seem well conceived in terms of her keel depth, rudder area and stern shape, and created a significant stern quarter wave when hard pressed at around 13 knots. 

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