Speed is of the essence for any competitive sailor, but keeping ahead of the pack in racing also means keeping up with the latest design developments, whether they affect the aesthetics of the boat for the better.
This is also true for the Mini Transat 6.50 race, also known as Transat 650, a solo transatlantic yacht race, an associated Mini Class that starts in France, covering over 4,000 miles. Since the last race in 2015, there have been some interesting developments in the boat design of the participants.
The Scow Bow
Classically, racing boats have been designed to be long and sleek to cut through the water with plumb bows aiding this, but today we see a new revolution taking place in the Mini Class with the ‘scow bow’ being used and in an effective manner.
The 2015 race sported these fuller bows, the top two designs being the Bertrand-designed Ofcet 6.50 and Verdier-designed Pogo 3, which are not as extreme in their design as the David Raison ‘scow bow’ that was used on the 6.5m Mini Magnum, but are still fuller than other competitors in that race.
Guillaume Verdier, naval architect, Verdier Designs, explains why the ‘scow bow’ was adopted for Pogo 3: “Those boats are so wide that when sailing they have a terribly excentered heeled waterline. It [the scow bow] actually reduces the distortion of the heeled waterline to be wide forward, plus it increases the dynamic waterline.”
The design of Pogo 3 undertook computational fluid dynamics (CFD) testing. “I did compare hulls CFD. I could also transpose part of the understanding that I had from designing other kinds of boats. Basically all boats answer the same questions of lift and drag,” Verdier adds.
The advantage that the scow bow brought to Pogo 3 was that it performed better on average.
Making the Boats More Stable
The scow bow has had many sailors in uproar about its aesthetics, the likes of which have not been seen since the introduction of the canting keel.
Simon Rogers, designer at Rogers Yacht Design says that scow bows do seem like a natural progression for the 6.50 design and will offer a lot of extra performance for sailors that use boats with this type of bow in racing.
One of the main performance factors that a scow bow will offer is more control of the vessel, he highlights. Rogers adds that “short fat hulls tend to stand on their diagonal and bury the bow. Fuller and ‘scow bows’ put volume forward and move the bow water plane further outboard, making the boat more stable and level fore and aft.”
Having this type of stability also means that competitors can take 5 to 10 miles out of the competition. “The ability to carry sail and keep the boat under sail is an important thing in keeping control,” Rogers adds. “They are also really good upwind because the water plane moves out and the bow doesn’t bury itself.”
- Extra volume forward (racing/leisure)
- Generates a lot less drag (racing)
- Can keep sail up for longer (racing)
- Keeps rudder in water (racing)
- More control (racing)
- Not very pretty (racing/leisure)
- Slam in head seas (leisure)
- Not great when motoring into waves (leisure)
Scow for the Leisure Market
Having a scow bow has definite benefits for the racing market, but will having a scow bow also be beneficial for the cruiser market? Afep Marine is one company that has picked up on this design feature and used it for its leisure market in its Rêvolution 29 design.
The Afep Marine Rêvolution 29 design was inspired by the David Raison Magnum design the company has highlighted. Having more volume forward has allowed the design of the Rêvolution 29 to have 30% more habitable space inside.
The boat doesn’t plunge.
“This innovation in recreational boating enables us to offer customers vessels with good performance, stability and comfort” explained David Roy, Afep Marine founder to NauticExpo e-Magazine. “The principle is rather simple. The boat’s beaminess fore and aft offers great stability and makes it possible to carry a lot of sail, even in high winds.
The boat doesn’t plunge. The waves don’t slow it down because it rides over them. Because of its significant forward volume, the boat handles the waves much better.“ A concept that seems to be quite successful, as Afep Marine is now planning for a Rêvolution 36 and 42.
Rogers notes that putting a scow bow on a cruiser may generate adverse effects such as slamming in head seas and reduced comfort when motoring in to waves.
Scow bow’s are presenting a unique advantage in the racing market, but as to whether they will take off in the leisure industry is still yet undecided, Rogers adds that “it’s whether customers will accept it. It’s more of a fashion thing.”