water world

Fully crewed IRC yachts increasingly use water ballast to reduce the weight of the keel bulb without sacrificing stability upwind and when power reaching. Despite the ubiquity of such systems in short-handed racing the top IRC teams have found scope for innovation and improvement. RORC Commodore James Neville’s new Carrington-built Carkeek 45 Ino Noir, for example, has a water ballast system with 500 litre tanks on each side developed by Hamble, UK-based Diverse Performance Systems. This is an evolution of the setup on Niklas Zennström’s Carkeek 52 Ran 8, which launched last year.

‘We’ve made it neater, lighter, and more compact,’ says Diverse MD Nick McGarry. ‘We’ve also added our own pneumatic actuation systems with on-deck push button control.’ Instead of the stand-alone valves used by Imoca 60s, custom units with pneumatic valves are integrated with the manifold. This reduces weight and complexity, streamlines installation and allows for a very simple actuation system on deck.

Other key elements include a pair of hull scoop valves that minimize aeration at speed and retract when not in use, plus a high capacity 24 or 48V electric pump rated to move up to a whopping 900 liters of water per minute. An extra-large crossover pipe transfers water from windward to leeward in only five to 10 seconds when tacking. ‘We worked hard to make tack speed as fast as possible,’ says McGarry, ‘so the system works flawlessly for inshore racing when decisions often need to be made at the last minute.’ Read on.