One of the questions that new paddlers frequently ask (as well as a few veterans) is where do I position my fin? Before answering this you have to determine what type of paddling you will be doing. Will you be paddling a long distance with hardly any turns? Will you be negotiating a tight river with a lot of bends? Will you be surfing?
Modern stand up paddleboards generally have an adjustable center fin. By simply loosening the screw the center fin can slide forth and aft in the fin box. If you own a Three Brothers board, your board will have an adjustable center fin box as well as two removable side fins. So what position should be used for what conditions and when do my side fins get used?
Your stand up paddle board will respond differently depending on how you position your center fin. Generally, moving your center fin all the way forward makes the board more agile and easier to turn. You would want to use this position if you were paddling in tight quarters or negotiating around other paddlers such as down a crowded or narrow river or a racing on a tight course with many turns.
Positioning your fin all the way back within the fin box will cause your board to track straighter and be less prone to wander side to side. Of course the added tracking stability means a bit more effort must be used to turn. If you are planning to paddle a longer distance, like on a group tour, then moving your fin rearward would allow you to switch sides less often.
Like life, standing on your board or doing yoga, most find being centered is the way to go. It affords the best of both and keeps your board handling neutral while still tracking fairly well.
But when do I use my side fins? Side fins or “side bites” are typically reserved for surfing although some will remove the center fin and just use the side bites in flat water. The side fins allow you to carve more aggressively while surfing. This is also the time to consider making sure your center fin is all the way forward.
Overall, SUP fin placement and board handling are intertwined. Once you know what your conditions will be you can set your board up accordingly.
