This question comes in frequently and in many variations, a common one being, "why 4'10"?", implying that 4'10" is too small for the person asking. The reason Moda's first available surfboard is 4'10" is not because we think 4'10" is the ideal size for everyone.
The quick answer is because, as the primary Moda surfboard test pilot, the boards have been designed for me at 5'6" and 125 pounds. The first couple Moda prototypes were 6', but they were too difficult for me to turn because of so much submerged rail. The solution was cutting down length to reduce the amount of effective rail, and at 4'10", the boards were finally maneuverable enough for me to surf the way I like surfing. I actually think my ideal length is 4'4", but that's a discussion for another post.
But didn't reducing length also reduce buoyancy? Yes, of course it did, but in a good way because at 4'10", I can finally handle the board. It does what I want it to do. It responds instantly to my movements and shifts in weight compared to the larger prototypes. I can duck dive it. Yet even at 4'10", the Moda surfboard floats me noticeably better than my favorite 5'4" conventional PU surfboard (beaded polyurethane foam and polyester resin).
Moda surfboards are more buoyant than conventional surfboards because we use extruded foams which are more buoyant than beaded foams. And, because the extruded foams we use are closed cell, they don't bear the extra weight of an outer fiberglass layer required by conventional surfboard foams. In short, compared to conventional surfboards, bodyboard construction means Moda surfboards have spare buoyancy we can experiment with in our designs. We've had guys up to 185 pounds shred the 4'10", though I think it reasonably maxes out at 160.
Since the Moda 4'10" has been tested way more than any of our other designs, it's available now because we know it shreds.
But for those who feel that 4'10" is too small, I'm happy to say that Moda is currently testing bigger sizes: a 5'6" for 160-200 pounds, and a 6' for 200+ so a wider range of people may soon enjoy snowboard-flex in surf. It's a test because we don't know if bigger sizes will work properly. So far, they have. They didn't in the past, but we've learned a lot more about flex and surfboard design since then. And, it'd be useful to know what the limits are for a surfboard to be too small or too large for flex to work properly.
Trying to implement what works at 4'10" to a board that's 6' is tricky because flex doesn't scale easily. Increasing overall board length completely changes force and pressure gradients and lever points for the core. Even without flex, increasing length means adding width to maintain proportion. This multiplies the planing area which definitely affects how the board behaves.
The way to scale flex is by doing solid empirical benchmarking. After some iterations, we should be able to develop the math to help us scale flex to different sized surfboards.
Scaling flex is tricky, but not impossible. It'll take time for us to get it right, but my sense is that it'll be worth the wait.
Want to demo snowboard-flex in a 5'6" or 6'? Let me know @modasurfboards on Twitter!