Catamaran technique - part 3

In the opening article two weeks ago, Tornado legend Mitch Booth explained the importance of having the crew trim the mainsheet on high-performance catamarans. Here, Mitch's 'other half', Herbert Dercksen of the Netherlands, talks through his approach to mainsheet trimming. Trimming the mainsheet varies according to the conditions. Initially, I'll try to move it as much as possible. Then gradually I’ll reduce the range of movement. This is the best way of getting ‘in the groove’ - by starting wide and finishing narrow. When we’re just getting on the trapeze and looking for power, I’ll move the sheet just 6 inches or so, but in big waves it’s more like a metre. It can vary from tack to tack too, depending on the wave conditions. What I’m aiming to achieve is to give Mitch the opportunity to steer up and down. It's experience and feel that tells you what's right, plus a bit of talent. We talk about mainsheet tension between us. Sometimes I can't feel the helm and Mitch will say the rudder is stalling, but 90 per cent of the time you do it by feel. Wind, waves, sheet There are three factors involved in mainsheet trimming: the waves you see, the wind you feel, and the tension of the sheet. If there's a big wave coming three waves ahead, you have to pull it in hard, to lift the hull in time. It takes a lot of training, and the more you train the more you get used to it. Aim to do everything by feel and don’t rely on looking at stuff. You can check if the tell tails are flowing, and you can check the depth of the main, but if you can do things by autopilot the better off you'll be. Some sailors use a