With most wake surf boards, to generate additional speed while riding the wave, apply weight to your front foot. This will drive the board forward towards the boat. To slow down, apply weight to your back foot. Generally, when you apply weight to your back foot to slow down, you will need to put weight on your front foot again to speed up a little. It is very important to master these fundamentals first as everything else in wake surfing is based on speed control (weight transfer).