The parlous state of mainstream big wave gun surfboard design and why the FP 13 Hawaii challenge board is light years ahead: spherical rocker, displacement tails and other magic remedies.

Even as late as 2004/5 the level of understanding of big wave guns was so low that much of the carnage at Mavericks was blamed on a mythical 'suction zone'.  I wrote some long essays on Swaylocks on the subject and how it was really to do with too much toe in and cant which was stopping the boards from turning. The typical  side fin cant and toe in which was used in smaller waves was cut and pasted on to big wave guns and couldn't handle the speeds involved at Mavericks. Of course the industry legends all denied this and I was abused  for saying it but the message got through after a while and now it is common knowledge that zero or low toe in and cant is required for faster speeds and bigger waves.

At present most big wave paddle in guns are still based on the tail riding shortboard concept. This is a fundamental mistake in my opinion, as the tail riding position is inherently unstable and gives poor control.  With a more central riding position far better control can be achieved. In addition the wider tails used in such boards have the problem that because the planing lift produced by the tail  ( and fins) increases by the square as speed increases, it becomes increasingly difficult to turn the boards at higher speeds, as the rail to rail leverage exerted by the tail increases drastically. That's why we see riders having to slow down at the bottom of the wave to turn rather than turning as they go down the face, and it's also why we see so many riders failing on the takeoff, parachuting down the face into oblivion due to inability to control the planing area which is all concentrated at the tail where they are standing,. .. . the nose is uncontrollable from the tail particularly  if wind gets under it. Nose weights do not solve the problem.  Tails ( currently I'm the only one doing this ) which are extremely narrow ( thus having low planing area and very little rail to rail leverage ) but which have substantial buoyancy avoid this problem completely regardless of speed, as buoyant lift does not increase as speed increases.

Rocker wise the central riding position can be achieved with variety of rockers including those with very flat tail sections, but the board we sent to Hawaii follows one of our most successful rocker and planshape combinations which we've been using since 1995 ( the circular arc or 'spherical' rocker whereby the nose and tail rocker measurement is identical and the widepoint in  planshape as 50% back from the nose ) This rocker and planshape combination is ideal for the central riding position. I've been consistently mocked and attacked for using this setup ever since the beginning,( and I've been publicly singing its praises for the past 15 years ) but the fact of the matter is that it's a very good system.  I noticed only last week that  the maker of 'Stretch' surfboards has announced a new innovation ( supposedly new anyway) namely the spherical rocker and  50/50 planshape proportion  inorder to achieve a more forward, central riding position on his guns. So the message appears to be getting through again !

I've been singing its praises for over two decades  and it's good medicine provided that it's matched to the planshape correctly ( widepoint around halfway up ).The continuous ( also known as circular arc or spherical rocker ) rocker was bagged by shapers for many years because it isn't complicated enough, it's like the crew cut of surfboard rocker no curling pins or hairspray required !

I use two kinds of spherical rocker, a true spherical rocker and a tweaked one. In both cases the nose and tail rocker measurements are identical, and the widepoint is at halfway. The true spherical rocker is just that, a circular arc. the tweaked version is spherical from the wide point back but has a slightly elliptical rocker forward of the wide point.... this doesn't affect the overall nose rocker measurement.

There's a lot more to this particular design ( the Roy Stuart surfboards FP13 which is in Hawaii ) for example the displacement or sinker tail which allows the tail to be sunk for control during steep drops or turns, and the use of large elliptical planform 'spitfire' fin area with a narrow tail and circular arc tail in planshape for presentation of the fin at angles which provide significant planing lift when angling and dropping on steep walls.

The use of a longer wider board with a parallel profile enables good paddling power while keeping the board thickness down as much as possible ( the FP13 is only 2.25" thick ) for greatly improved control and superb flex .

Weight distribution wise the distribution is approximately proportional to the planshape area, thus there is significant weight in the nose. This, combined with a long nose, provides penetration and control by allowing the nose weight to guide the board's glide path via the releasing and engaging of the rail. This rail release is best achieved via extremely soft rails, I use a continuous 50/50  rail section for smoothness and predictability. A 50/50 rail behaves the same way when entering or leaving the water. Predictability and control lead to confidence and ease of correct wave positioning, which in turn leads to speed and wave making ability.

The central riding position of the Future Primitive 13 footer and the 12 foot Ghost is all about balance and control

Roy Stuart