Channels versus concaves?
If you examine at any surf, kitesurf, windsurf or SUP board, channels and concaves are a feature used on all types of boards. Concaves & channels have been used since the birth of the Kite Alaia boards. However, the harsh angles of a channel will make glassing your Kilaia much more difficult and necessitate the use of a vacuum-bagging system to ensure the glass-fiber fits smoothly into the harsh angles to avoid any bubbling.
It’s much easier to use a concave in the tail section of circa 7mm which flattens out towards the rails. This will increase the comfort level considerably and the glass-fiber application is easy once the concave is in place. We would confirm that if you choose to use a single fin, channels or a single concave will make your board much more comfortable.
As shown above, Alaia boards use single & multi concaves to assist in hydrodynamically channeling the water to exit the hull faster and also create water surface grip. At present there are no hard-and-fast directives, as to which combination of channels/concaves are the most efficient – our collective knowledge base results will hopefully validate this.
These pages will be updated as more people contribute with their findings.