NEW FLEET OF EXTREME 40 CATAMARANS IN AUSTRALIA
NEW FLEET OF EXTREME 40 CATAMARANS IN AUSTRALIA
Although the Extreme 40 is old-school compared to state-of-the-art multihull sailing, performance on windward/leeward courses is excellent.


Sail development
Over the past three years, I’ve learned a lot about how to sail these boats and how to improve the sails to make them even more user-friendly. Before I started as mainsheet trimmer on Boatworks, I had assumed that the 1:1 hydraulic mainsheet had contributed to the many capsizes on the Extreme tour and expected it would be difficult to manage. To my surprise, I quickly learned that it’s very effective; both to achieve the required leech tension, and to dump power when required. Because the boats sail such tight apparent wind angles both upwind and downwind, the mainsheet is only eased significantly for bearaways or slow speed manoeuvres. Otherwise, the continuous traveler becomes the main control line. The original North mainsail design required reefing a little too early in the wind range and left us struggling for upwind speed if overpowered, due to the extra drag. We were also carrying additional weight (outboard, safety gear, a heavier crew) so the boat needed a little more horsepower downwind. And we weren’t as fast reaching against other multihulls optimised to the OMR Rating rule, since those boats had multiple forward sail options to cover all sailing angles. Not wishing to complicate the boat, we decided to ignore the reaching issue and focus on upwind and downwind improvements. I designed a new mainsail with increased head width and much less mid-leech roach, which helped improve leech twist control. That meant a less draggy feel in the higher wind ranges, and we could carry a full mainsail in more breeze. As the boats power up earlier than most, we felt sacrificing some light air performance was worth it for a more user-friendly wardrobe better suited to our east coast seabreezes. For the jib, we decided to keep the original geometry but added a little more depth. The Downwind Zero was given slightly more forward luff projection and depth, for increased and earlier downwind power.
Heavy Air Jib Design for 2019
With four boats wanting to make the most of windy conditions up north, my project for this year was to develop a shorter hoist jib that would further increase our raceable wind range. Piggy-backing off the work North did with the AC45s and AC50s, we produced three paneled sails and one 3Di RAW jib. The new sails gave the boats great upwind speed with a lower center of effort, which reduced traveler movement. The other advantage was less power forward of the mast, giving the boats more control downwind even when wind against tide made for a challenging wave state. We used the heavy jib with both full and single-reefed mainsail configurations, something that will be tested further as we come into the summer months.
Fleet Building
From here we hope to continue building the fleet, working toward our own one design division with specialized courses at bigger events like Hamilton Island Race Week. We’d also like to continue racing in mixed Multihull events around the Asia Pacific region. All the Formula 40s come with their own 40ft container, so it would be fairly straightforward to attend regattas around the Pacific, and even get over the ditch to New Zealand. The current owners are now drafting a class constitution, and rules are being developed that will help keep a level playing field for new owners. There are four other boats for sale at various price points globally, and we are actively seeking new owners and crew to join the fleet. Please don’t hesitate to get in touch! Ben Kelly