Development of the V12 Surfski

The Idea behind the V12

When we designed the V10 surf ski, some of the earlier versions were actually faster than our final design. We opted to de-tune the faster versions to increase the stability of the V10 and make it appeal to a wider range of paddlers.

With this in mind, I always thought – what if you had a skilled paddler in small to moderate conditions? Wouldn’t it make sense to sacrifice a small amount of stability for increased speed?

Thus the goal of the V12 was to make the fastest surf ski possible. The target would be for flatter water, or moderate conditions that are encountered in many parts of mainland USA and Europe where surf skis are paddled. Going back to the drawing board, I decreased the water line width and played with the cross sectional shapes & rocker profile to create a faster hull. I kept in mind that many races are a combination of flat and rougher water (such as the Mayor’s Cup in NYC that is typically flat for 75% of the race, but conditions pick up considerably the last 10 km; or the US Surf Ski Champs held half in San Francisco Bay and half out in the open ocean.) I wanted the V12 to have enough reserve buoyancy and secondary stability so that it could handle rough water when necessary.

After several iterations, our calculations showed the V12 to be approximately 2.4% faster than the V10 on flat water – a significant improvement. Further, for an 80 kg (176 lb.) paddler, the V12 is faster than an ICF sprint racing K-1 between speeds of 9.7 to 16.5 km/hr. (6 to 10 mph), while being significantly more stable and capable of handling rough water.

{A special thanks to John Dixon who helped with much of the number crunching in calculating the resistances.}

Don’t let the wider looking bow fool you – this boat is fast! It’s narrow at the waterline, with flare to give added buoyancy and stability (more on that later).

What’s up with the Bailer/Drain?

Venturi drains are a considerable benefit for paddlers in the open ocean who are constantly having waves dump water into their cockpit. However, the venturi draining action comes at a price. The flow disturbance on a surf ski hull can increase drag and result in up to 1% speed loss. If you will be paddling in calmer conditions without getting water into the cockpit, why should you put up with this speed penalty?

We installed a bailer on the V12 – of the type commonly used in marathon racing canoes in USA. This gives a smooth hull and faster speeds when draining is not needed, with the ability to open up and drain the cockpit when necessary.

In testing we found that when the bailer is fully open, it drains significantly faster than our standard venturi. However, it also creates more drag. A fully open bailer creates about twice as much drag as our molded in venturi (but drains the cockpit 3 times as fast,) resulting in up to 2% speed loss. Luckily, the bailer can be opened part way, which still gives good draining with less drag increase. The bailer must be opened up at least half way (or a little more.) At 50% or less open, the swinging gate cannot open to let the water out. At 55 to 60% open, the bailer still drains as fast or faster than our molded-in venturi, with similar or only slightly increased drag.

Thus for calm water, we recommend keeping the bailer closed at all times, only opening up if water comes into the cockpit. For steady open water paddling, keeping the bailer at 50 to 60% open will provide good continuous draining while eliminating the need to open and close the bailer each time the cockpit becomes flooded. The full open position should only be used when you want to drain the cockpit quickly and then closed, or pulled in to the half open position once the cockpit has drained.

An added benefit of the closed bailer is that water will not back drain into the cockpit – eliminating the lap full of cold water often experienced on the first stroke with surf skis in colder climates! Even with the bailer open, the swinging gate greatly decreases the back draining of water.

It is possible to remove the swinging gate so that the bailer can drain effectively at lesser openings (say 30% open) to still give some draining action with decreased drag penalty. However, removing this flap will allow water to back drain into the cockpit when the bailer is open while sitting still or paddling at slower speeds.

Why is there a cover over the front of the cockpit?

I wanted to re-create the close catch position of K-1’s in this surf ski. Doing so required dropping the seam line at the front of the cockpit. While it gives a great catch at the start of the stroke, it can allow more water into the cockpit in some conditions. The cover makes for a drier ride and less need to open the bailer in moderate choppy conditions. The cover also prevents catching the paddle blade on the steering pedals or your feet (for those with big feet) – a possibility in the V12 because of the narrowness at the paddle entry position.

Surprise – the V12 surfs and works well in rough water!

When I design a new boat, I analyze data as much as possible, but never know 100% how it will perform in the real world. This is especially true in rough water conditions – which are much more difficult to model than flatwater performance.

Therefore we shipped two V12’s to Mauritius to let some of the team Epic paddlers test them out in a variety of conditions. We were pleasantly surprised, the boat performed well in all conditions! The flare above waterline provided enough buoyancy and secondary stability, that waves were not a problem. In fact it maneuvered and handled as well as any surf ski we’ve paddled! We paddled in conditions up to 4-6 ft (2 meter). It still remains to be seen if the V12 works as well as the V10 in Molokai type (8-12 ft or 3-4 meter waves) conditions.

Fit of the V12

The V12 footwell is sized between the V10 and V10L. Thus it will fit paddlers from about 5’1” to 6’5” tall (1.55 to 1.95m).

After feedback, prototypes and testing of seat shapes, we modified the V12 seat to provide more comfort. There’s more room for the coccyx and slightly less tightness at the hips.

But how stable is the V12?

The initial stability of the V12 is slightly less than the V10 and V10L. However, the V12 secondary stability is greater than either of those boats. Thus it will depend on the paddler. For tentative paddlers on calmer water, the V12 will likely feel slightly less stable than the V10 or V10L. For aggressive paddles and/or rough water use, the feedback is that the V12 is very similar in stability to the V10 and V10L.

Who should use the V12?

• The V12 is the surf ski for those who want the fastest boat available. For flat to moderate conditions the speed of this ski is unmatched (with the bailer closed it’s approximately 3% faster than the V10).

• The V12 is perfect for paddlers with good stability skills and flatwater or marathon sprint crossovers. They will appreciate the speed (faster than a K-1 at speeds of 10 to 15 km/hr), cockpit and paddling position.

• The V12 is best for highly trained and skilled paddlers. While it has a 3% or more speed increase above 11 km/hr, the speed increase is only 1% to 2% (depending on bailer position) at slower speeds (8-10 km/hr or 5 to 6.2 mph).

• Lighter paddlers and more tentative paddlers may find the V10L more stable.

• Extra tall paddlers (over 6’5” or 1.95m) will fit better in the V10.

• The jury is still out on really big water surf performance. The V10 may still be king in large (8 ft or 3 meter plus) conditions.