The air density is about 850x smaller compared to the density of water. Windsurfing fins are vital and the most underestimated part of your kit. There is no other part which has some many aspects influencing your ride then fins. Ever considered how the fin outline, rake, material flex, twist and shape of the the fin is influencing your ride..? No worries as we walk you thru all important parameters so you can be assured to make the right choice whatever your board and rig combination.