World’s Largest Sloop ‘Can’t Sail’?
by Nancy Knudsen on 1 Oct 2006

Mirabella V foredeck SW
What a beauty. 292 feet (89 metres) in the mast, 247feet (75.22 metres) long and 48.5ft (14.8metres) in the beam. She can do 17-18 knots with ease, and 10 knots in a 10 knot breeze. Mirabella V is not only a beauty; she’s the world’s largest sailing sloop. So what’s this we hear about a ‘problem’?
'Well,' say the experts in the bar, 'Did you know that every time you want to tack that boat, you have to lower the mainsail to the first reef?'
'Sure,' says another, who’s been in the bar at the end of race day for years, 'Ain’t that just ridiculous?'
'There’s another thing,' says some-one from the next group, whose just heard the name Mirabella V used, and can’t wait to join the conversation, ' Did you know that you can’t tack the boat without first furling the headsail, then letting it out on the other side?'
'Actually,' says another, 'I’ve never seen her sail with her full main up – she’s ALWAYS got a reefed main.'
The group are all shaking heads into their beers now. 'What a waste of money THAT was.' Finishes another, and there’s just no more to be said.
It wasn’t long after that that I found myself in conversation with the designer, Ron Holland, who has a long history of designing wonderful sailing boats. Could he really have designed a dog? So I asked him:
'Well,' said Ron in his soft drawl, 'If you query rolling the jib up to tack, really most big boats do that. It’s normal to at least partially roll up the jib. It saves the jib from wear.'
'As far as the main is concerned, this boat is unique in that it has a huge roach, and therefore to tack with full hoist mainsail you have to lower the main to the first reef point so that the sail will clear the backstay. The reason the boat was built this way is because we wanted her to sail well.
Most really large boats don’t go anywhere in light air. We wanted Mirabella to sail in all conditions. Now it’s a lot of boat to get moving - even though she has shallow hull lines, only 2 metres deep, she displaces 700 tonnes - so you need a lot of sail to get her to accelerate well.
So the sailing strategy of Mirabella V is to get her up and going quite quickly with the full main – she can do 10 knots in 10 knots of wind.
'However, once she’s sailing, she generates apparent wind very quickly, so the normal plan is to reef her down once she’s reached a good speed. She can easily do 17-18 knots with a reefed main.
'You must remember that we never plan to use a spinnaker, so you need the good sail area for downwind sailing – she also has three headsails, the largest of which negates the use of a spinnaker, so it’s all part of the overall plan to end up with a good fast sailing yacht.
'To say that she ‘doesn’t sail well’ is a bit outrageous. It’s quite clear when you look at the shallow hull and high aspect ratio of the keel that we were very much interested in her sailing ability. I think the comments you have mentioned are as much as anything a misunderstanding of the philosophy behind the design effort that went into Mirabella V.
'Mirabella V is a boat that sails well in light air, and that’s a really big achievement. Most large cruising boats don’t accelerate well, and Mirabella V does. The yacht, of course is out for charter some of the time, and during charters she does often sail around with one reef in the main – charterers are often looking for comfort not speed, and 12 knots or so is just right for them.
Well, there you go, drinkers at the bar – you learn something every day!
For full information about the lovely Mirabella V, go to her website
If you want to link to this article then please use this URL: www.sail-world.com/28442