The picture demonstrates part of the benefits of the RSS technology. While the main benefits really need to be felt when paddling a board, you can see that the board has slightly less sag with the RSS battens. The board is extremely rigid without them and they are not essential to the use of the board, but they offer a 30-50% increase in stiffness when riding with them installed. In case you were wondering, she is 150lbs.
Their primary function is to distribute the weight of the rider over a larger area. At the feet, as this is where the majority of the flex originates, the battens work against the downward force of the rider to produce a stiffer board by preventing flex – similar to how a stringer works on a hard board.
The stiffening battens are removable for easy board rolling and can be stored in the carry bag for transportation to and from the water.
Not all models in the Red Paddle Co range have them, only the less than 4″ thick and Race boards. The 4.72″ and 6″ thick boards are stiffer due to the 1-2 extra inches of thickness and are more general cruising SUPs, while the Race board has them for that extra little bit of performance. See all the RSS equipped boards.