JEM Watercraft

I'm fixing to start building a 14-32 Paddle Board and am planning on installing a single 10-1/2 inch fin box along the center line. My question is how far from the aft end of the board should I put the box?

Also is there any preferred fin design for flat water paddling where manuvaribility is not a big concern?

The aft end of the box should be about 12-14" from the stern. The shape is paddlers preference. But the shape won't have major impact for just straight line paddling. Nice article here: http://www.activeweekender.com/sup-fin-placement/

Great- thanks!