Thanks for your answer.
I see what you mean but the same (but may not perform well as a longboard in low wind because of it's width) counts for the Rio if I understand you correctly. This one is also width and has large volumes. Next to that is has also a daggerboard. If I choose for the 151 do I need a larger rig to surf on days with low winds ? what do you recommend ? or is it not possible to surf with low winds on a 151 ?