Vincent Riou: the quest for the right balance between lightness and power

President of the Technical Committee, Vincent Riou, skipper of the winning boat PRB, gives www.imoca.org the low-down on the lessons learned from this Transat Jacques Vabre and the evolution of the IM

Has the race given you any new perspectives about the evolution of the current measurement rule? Yes, inevitably we’re continuing to learn on the current boats. I’m not sure that it’s a general sentiment within the fleet, but what you can observe about the current boats, particularly on the two most high performance boats in this transatlantic race, prior to Macif’s mast breakage, is that even in the use of the old boats, we’re gearing towards the trends that influence the new craft. In concrete terms, this means not necessarily using all the power a boat has, but above all trying to find the right balance between the power and the weight of the boats. Since I’ve been sailing on my latest prototype, the more time that passes, the less ballast I use in my boat and the lighter I try to sail. I would even go so far as to say that even though we continue to build boats according to the measurement rule, which has existed up till now, the power factor, that was limiting for everyone concerned in the construction of the new boats, will no longer be an issue, as PRB or Macif never use the boat’s maximum righting moment. As such, I think that the new boats won’t necessarily be lighter in terms of overall weight, but will be in sailing trim with less use of ballast tanks, etc. That’s the current climate and I think that the measurement rule as it stands is evolving and is synonymous with developments in the way we sail and get the boat making increased headway, within the limits of a 60 foot length and a beam of between 5 and 6 metres… That’s my initial conclusion.

The reliability of the masts:

I think that today all the fleet has reliable masts, even though Macif dismasted. They remain race boats with precise definitions of use in respect of the rig, which you can’t depart from. There’s no such thing as an unbreakable mast. Ultimately, there was just one rig issue here and the cause is known.

The reliability of the keels:

I’m delighted that we’ve made a strong stance for the future. I’m also happy to forgo my fabricated keel and switch to a really reliable version, because like all the people who use this technology, which isn’t bad, we must face facts and recognise that it can be overly prone to problems with set-up and fatigue, considering what we put it through. It was high time that we arrived at a situation where we no longer need to ask questions about the risk of keel breakage. The decision to go with a forged steel keel is something simple and effective, which will enable more boats to make a race finish as they will be more reliable.

The power of the boats:

The problem with power is that this translates as more weight. It’s a vicious circle. Today we’re trying to find the best compromise between power and weight, and this compromise means that the power we have on our boats in terms of righting moment isn’t fully utilised. It’s just an observation. However, I find that it’s a rather good thing to know that you can sail with more of the focus on refinement rather than power. In the end, sailing by working harder on the sail and daggerboard set-up, etc. is more intelligent than simply filling the boats with water and winding on the sails. We’re tending towards a little less sail area on the finer boats, which we’re trying to get airborne as much as possible. Indeed the sensations are better than simply powering up and winding on.

Old and new boats

The new boats are clearly those built since 2011. However, the boats from the previous generation are optimised and there aren’t massive differences between them because we’ve learned to make the best possible use of them. On PRB, I still have the same keel, the same mast and the same daggerboards as I had when she was launched, but the boat goes a lot faster because I’ve learned to control all the subtleties of the boat’s power / weight ratio. That’s mainly where a boat’s subtlety in terms of speed stems from.  There is still room to improve, but not that much because I think we’re getting to the end of the concept. By doing more sailing, you’ll always be able to hone the details on the boats, but we’re beyond the point of making sizeable gains.  The early boats of 2008 are becoming very old now, which inevitably means that there is a degree of separation between the more modern boats. In general, there aren’t many solutions for moving forward, but there is still some progress to be made. However, there is a certain harmony amongst the fleet, if you accept the idea that there are two divisions, as was the case in this Transat Jacques Vabre, where the fleet split in half. In this edition for example, there were two fine races within the main race. Today that’s the best we can achieve with a fleet where there is so much disparity in age. Today, in the same fleet we have boats like Team Plastique, which was built for the Route du Rhum 98 and boats like Macif built in 2011... a 13-year gap inevitably creates disparity, but that doesn’t prevent matches being played out at every stage, as is testified by the incredible finish between Alessandro Di Benedetto and Tanguy De Lamotte, who were just 9 seconds apart.

CF