Stand up paddle boarding (SUP) is a great exercise for stability and strength. It is however difficult to train out of the water, to build up the ability to try it out on water or just to get some good exercise. The client has a preliminary prototype (see pictures above); however, it requires a better attachment point for the resistance bungee. Currently, the paddle shaft bungee is attached to a fixed point about 250cm in front of the board, exactly on the centre line of the board. The angle between the paddle blade (the “catch’ phase) on the lateral side of the board and the centre-line anchor point is a problem.  

Bungee Attachment
In the real world on the water, the paddle stroke is parallel to the side edge of the paddle board. On the dry-land trainer board, the bungee is attached to a fixed point a couple of metres in front of the board (on the centre line) and the paddle stroke is no longer parallel to the side edge of the paddle board. The longer the bungee (i.e., the greater the distance from board to bungee anchor point), the less issue the user has with the angle of force. In other words, as the angle of the bungee line lessens, the paddle stroke feels more and more natural. However, the longer the bungee is, the more room the whole setup requires. This is a serious limitation. 

 

The client would use a short bungee (~200cm) to keep the system to as small a footprint as possible. To keep the bungee force vector parallel to the side edge of the paddle board, the bungee anchor point needs to move left when the user is paddling on the left side, then after a few strokes move right when the user switches the paddle stroke to the right side, and back and forth it goes. This lateral translation of the bungee anchor point would be ~1 metre.  This lateral translating anchor point would create a paddle stroke that truly is parallel to the side edge of the board.

Your task is to design an attachment point for the resistance bungee. The client already has a working SUP platform and paddle with bungee. The bungee must be as parallel as possible to the board when the stroke is being made on each side. The device must not take up a large footprint when in use and should be able to fold for storage. The system should be able to easily swap out bungees in case one breaks or for different resistances.