To Determine Your Seat to Feet Measurements,

Sit on the floor, make a fist, bend your knee.  Put the fist under your knee.

Your feet should be kind of relaxed and pointing in about a 70 degree angle ( not straight up 90 deg).

Now mark the floor, straight down from the ball of your foot. Not where your heel ends

because the footwell on the waveski angles foward.

Now mark the floor, straight down the small of your back, same here the seatwell angles back.

With a tape measure, measure the distance. (An Average Measurement is 41.5" for a 5'10" person)