Following a debut season of mixed performances on the 37–footer Jump Juice,Conor Phelan went back to the drawing board for 2007 removing the trim tabbed keel and replacing it with with a traditional fixed fin keel.
The technology is in poplar use in America's cup boats but very new in smaller racing boats like Jump.
Based on a development of the Ker 36, Phelan's boat has a similar layout,though it was originally fitted with a trim tabbed keel to maximize her IRC competitiveness and take her to the top of the rating band for Class 2 in the Commodore's Cup.
The Royal Cork crew found that in flat water with strong breezes the tab worked as well as the computer model suggested, but as soon as there was any kind of choppy sea the tab became more of a hindrance than a help.
"As soon as it got sloppy it became really difficult to keep the boat in the groove" according to Mark Mansfield, Phelan's helmsman.
The trim tab is a 'flap' - an adjustable surface like the flap on the trailing edge of an airplane wing - it is attached by a hinge to the trailing edge of the keel.
When the boat tacks, the tab is swung from one side to the other, around 5-12 degrees either side of centreline. This gives the keel an asymmetric shape that produces more lift.
It also produces more drag, but if designed and used correctly, the extra drag is more than offset by extra lift - meaning the boat goes forward more and sideways less.
Last month Phelan (steering) and Mansfield (on tactics) raced in Kinsale's Matthews Chandlery-sponsored league and won, counting four straight firsts in a testing range of conditions between 12 and 18 knots against their
Commodore's Cup team mates.
Reverting to a normal keel configuration now, the Jump Juice crew say they are as quick if not quicker through the water. It's also easier, says Mansfield, to keep it in the groove.
The removal of the trim tab has also given them a handicap advantage of 40 seconds in the hour, a significant saving at Commodore's Cup level.
Next home in Kinsale was Eamonn Rohan's Blondie counting four second places. Anthony O'Leary was third with his new boat, Checkmate, another Commodore's Cup boat, finished fourth.
Phelan was not the only one making modifications. O'Leary's Antix Dubh (ex Dark Angel) has had a substantial refit and is sailing with a masthead chute. Blondie was in her 2006 trim.
The results and the modifications have provided plenty to chew over, given that this week's meeting of owners for the 2008 Commodores Cup revealed several are already considering new builds.
Juice will be among a strong Cork representation in class zero at Volvo Dun Laoghaire Week in eight weeks time, where entries are expected to reach 300 by next Monday when the early entry discount closes.
A feature of the 2007 Regatta is the first appearance on Irish waters of the TP52s – three have entered the Super 0 division with the news that top Irish skipper Colm Barrington has acquired Flash Glove and will race against
Paul Winkelmann’s Island Fling from Hong Kong and Benny Kelly’s Panthera from Royal Corinthian YC.
UK entries to the regatta – around 30 to date – are set to make a determined challenge for honours in several of the 26 classes; most notably perhaps in the J109s, also racing for Irish championship honours.
An enthusiastic take-up by the UK class association looks certain to push the newly-established Irish JI09 class into double figures. The class will race as one-designs.
The new class captain is Chris Power-Smith of the Royal Irish YC.