This series of articles talk about racing under a rating rule, which is not just about what you know. Being an equipment-based sport, sailing is also about what you have. The foils and hull, the rig and sails, all play a role in making your boat go fast and rate well under systems like CBH for trailerable and sportsboats, or IRC and ORC for the bigger boats.

Julian Bethwaite designs fast sportsboats boats and Billy Sykes is with North Sails. Both are experts in the field, and they understand yacht racing and what things make it go fast.

What are the principles of producing a fast boat to race under a rating?

• JB: I tend not to worry about the rating, for two reasons, we sail under 2-3 different rating systems, so it's a bit of an issue as to which one you pick. I tend to just design a boat, trying to always optimise the design to maximise performance. You always are confronted with a myriad of choices, curves, vees, flats, large surface areas, small surface areas.
  
  First thing to do is work out what you actually want from a boat, be it a Hobart or just harbor race, likely wind conditions, water state. An example is a FR28R, designed in Holland, great on the Ijsselmeer, but at Airlie Beach or Magnetic Island Race Weeks, you have to stack it forward to keep the bow in, or it slams. I would have hoped that if it had been designed for Australia it would carry more Vee forward, but stacking it forward still works, not ideal, but quite okay.
• BS: Looking at a yacht's strength vs weakness in all conditions, upwind, reaching and downwind. What the owners campaign goals are for competing in Inshore, coastal or offshore racing. Gauging the competition and deciding what the target rating (TCC) the owner has in mind.

What features make it go fast?

• JB: Quite anal attention to detail and sticking with a philosophy that gets you to screw the design one way or another based on a strong idea of what it actually is you want.
• BS: Sail weight, sail range, sail handling for campaigning the yacht either fully crewed, partially crewed or 2-handed racing.

What equipment helps speed but isn’t necessarily rated?

• JB: Lack of bulb weight [under CBH], if you sail a boat flat then bulb weight is irrelevant from RM, but great for inertia, so you minimise it and do what you want, but no more.
  
  Also optimising the boat for the "average" conditions and then adding say a Code Zero, that is smaller than your #1 spinnaker, so it's not rated, but can really give you some extra horse power when needed in light conditions.
  
  That being said, we have a Code Zero, and it has never really worked.  In the 2023 Bay to Bay we set it on one long leg, and yes, it pulled us nicely along, but no better than 2 sailing and then setting the A2.
• BS: Code Zero (75% mid girth) sails are measured as a spinnaker, but in fact are designed to be light air Genoa's to fill the gap between a headsail and spinnaker.

What do you wish a rating system would change in its approach?

• JB: We need to be making the sport fun and enjoyable and entertaining rather than a back-room skulduggery (and expensive) boffin vs boffin. Great for the boffins, they get to charge money for their knowledge. Bad for the sport because we end up with boats that are designed for the wrong reasons!
• BS: More education for new owners entering the sport and racing under a rating rule.

What design change do you think has had the most positive impact on boats’ performance?

• JB: Squarehead mains, if done well, reduces the mast height resulting in a rating benefit. They can be powered up and also can blade off. I think they massively increase user-ability.
• BS: Reduced rig weights, advances in engineering and better understanding of Carbon Fibre has seen the rig weights reduced significantly. The square top mainsail, being able to control twist better upwind and the addition of sail area for VMG running makes the square top the big winner. The square top also comes with split backstays generally lead to a winch this allows for easy adjustment to mast bend and forestay tension.

For information about CBH, IRC and ORC ratings click here.