Select to expand quote
Neil001 said..
Has anyone tried 5 small fins on a SUP. In small waves I put 3 in the back 3 slots and was great.
cheers
5 fins work well for very wide tailed boards.
Basically, if you feel that the board as a quad handles like a supermarket trolley (there is some yaw when the board is flat between turns), add a 5th fin, big enough to stabilize the trajectory. It can be a nubster to a full central fin.
But the bigger the central fin, the bigger the drag. Compromises...
In my experience 5-fins is only useful in very short boards. Otherwise the longer rail line is enough for directional stability.
Here is a 6'10" fish I rode often in 5 fins:


In action:
A longer board (7'11") with a central nubster:

Note that the late Greg Griffin has been advocating 5 fins or 3-fins-in-the-rear setups for years:
www.griffinsurfboards.com/product/modfish/www.facebook.com/profile.php?id=100057262636965&sk=photos