Sailing News from Ocean Sailor Magazine

Genesis of the Twin Rudder

Genesis of the Twin Rudder

‘It’s the ultimate Blue Water design crime’

If you want to go blue water cruising then buy a cruising yacht, if you want to win races buy a racing yacht. A racer-cruiser will never be both the best racing boat and the best cruising boat. That’s because the compromises made are compromises too far when it comes to producing a safe blue water yacht.

My beef isn’t that these boats are bad boats per se it is that they are bad boats when marketed as suitable for world cruising.

This design amalgam now affecting all modern blue water boat builders originate from the popularity engendered by sailboat racing such as The Volvo, The Vendee Globe, and The Jules Verne Challenge.

The evolutionary process has been as follows:

  1. To lighten construction by using lighter and stronger materials, such as carbon- fibre and a whole variety of aramid materials and alternative construction methods.
  2. To change the shape of hull and stern so that this lighter yacht can now plane.
  3. To widen the stern so that increased form stability enables the yacht to carry more sail area.
  4. To change the shape of the hull to a full delta ‘wing’ style, maximising the ballast ratio to lighten the yacht further and increase the sail area further.
  5. The payback for that is a stern so wide that, on the wind, a single central rudder is levered half out of the water, losing traction and therefore steerage way. Which leads us to:
  6. The use of twin rudders, one for each tack so that one is always fully immersed.
  7. So brilliant, now the boat can plane and sail exceptionally fast.

But hang on, we’re supposed to be cruising, aren’t we?

What has all of that got to do with a safe, comfortable, blue water cruising yacht?

Nothing at all.

However on the boat show stands, families are understandably impressed by cockpits big enough for a game of badminton; apartment-sized aft cabins; and dinghy garages, all features that are very different, and sometimes treacherous, spaces on a rolling, open ocean. 

The boat show sales folk will ask you to slip off your shoes, proffer the glass of Prosecco, then invite you below decks, but it’s below the waterline that counts: hull form, keel and rudder.

What, in my opinion, and in the opinion of many in the marine industry who still remain silent in the press, has occurred is that these design demons are now becoming standard, even with top brands that have, in the past, been synonymous with safe Blue Water cruising. The latest models from builders including Hallberg Rassy, Amel, Oyster, and Discovery, all have twin rudders.

A single spade rudder is vulnerable enough to the hazards of ocean sailing, but two, and what’s more two that are out of line with the keel, is simply asking for trouble.

It’s crazy to think you can sail across the seas and oceans of this world increasingly littered with debris, containers, logs and, thanks to wild life protection campaigns, inhabited by growing schools of whales without risking fundamental damage to one or other of these unprotected steering blades. 

Maybe not this week, perhaps not this month, but as your log clocks up the miles, sure as hell there will be a hazard with your boat’s name on it.

Dick Beaumont

Another sailing expert speaks out

Hallberg-Rassy ‘Gave Away’ Design Pedigree

Leading yacht designers’ Hallberg-Rassy ‘gave away their pedigree’ by switching to bolt-on keels and spade rudders, top yachting expert, Duncan Wells told Kraken News in February. 

Wells, who owns and sails an old-style Hallberg-Rassy with a long keel and skeg-protected rudder, said: ‘We all know spades can fall off. If you are going to punch through the rough stuff at sea then you want something substantial beneath you. The trouble is, these days, they all want to go faster…much faster and they gave away the pedigree when they made that change.’ Wells was delivering one of his popular Stress-Free lectures on boat safety at the Cruising Association HQ in London’s Limehouse. 

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