Andrew Preece waits tentatively for a speeding fine as he flies past the Sydney Opera House doing 20kts on Ellen MacArthur's new tri Castorama B&Q

‘Slow down, you’re speeding,’ shouted the crew of Castorama B&Q as I steered the boat at 20 knots past the Opera House and under the Sydney Harbour Bridge on Friday. ‘The speed limit is 8 knots and we’ll tell them where to find you when the speeding tickets come in.’

We were returning from a spectacular sail. Just hours after Ellen MacArthur’s brother Fergus named the boat in a night time ceremony beamed back by satellite live into the Schroders London Boat Show yesterday (Thursday) see news story here the design team, led by designer Nigel Irens, the core of the build team and the sailing team had been putting the 75ft trimaran through its paces properly for the first time since the boat was launched just before Christmas. The speedo danced around 30 knots for most of a perfect afternoon as the pressure was piled on properly for the first time after series of gingerly conservative early test sails. The boat did not disappoint.

Castorama B&Q is a beast but a beast genetically engineered for MacArthur to sail fast but safely single-handed. On a sail area approximately the same as the 60ft trimarans on the French circuit, the boat is 15ft longer, around two tonnes heavier and more than a metre narrower. ‘Most of that extra length is at the front,’ explained Nigel Irens. ‘And with more buoyancy up there we worked very hard to reduce the tendency for this boat to bury the bows and pitch pole in the way that the 60-footers do.’ A by-product of the extra boat up forward is that instead of sporting a precarious and often delicate bow sprit as the 60ft fleet do, Castorama B&Q has a section of mainsheet track and a headboard car running to the bow that will enable MacArthur to attach the gennaker tack in the relative safety of the pulpit and pull the tack to the bow without ever having to go out there.

Further aft the cockpit has been tailored to single-handed sailing with all of the winches concentrated around the centre of the aft cockpit that is just a short hop from the inside of the cabin. ‘It’s just four metres from the chart table to the mainsheet,’ explained Irens as he showed Yachting World around the compact but cosy and efficient cabin that will sport just a single bunk.

MacArthur proclaimed that single-handed records like the transatlantic and the 24 hour records are the immediate goals once she has sailed with the team to New Zealand, spent time working the boat up in Auckland before setting off with a small crew to Cape Horn where she will drop them and sail single-handed back to Europe. ‘We did that with the Kingfisher monohull four years ago and it was a very effective way of working the boat up,’ she said.

But the big question mark is the round the world record that everyone, including MacArthur, concede would be the ultimate aim. But on that one no one will be drawn. ‘Obviously the round the world record is something we are thinking about,’ she told the media at the launch on Thursday. ‘But we’d be foolish to say that it’s firmly in schedule until we know more about the new boat and how I can handle her.’ It won’t be long before decision time is reached however, as any attempt over the next winter would have to be under way in November or December.

In the meantime I’m still reliving a memorable sail and waiting on tenterhooks for the Sydney Harbour speeding fines to come rolling in!