Because some SUPs have a thread for the mast base but no centre fin, there are always problems maintaining height in light winds - especially when children are on deck with small sails. Duotone, Fanatic and Arrows offer the Add On Drift Stopper for 99 euros: two fins are lashed to the board with a strap - which works perfectly.
The rail under the board is adjustable in length, we pulled the webbing really tight and threaded it through the carrying handle on the top of the board. Our test has shown: The centre fins do indeed provide enough surface area to keep the board cleanly on course and minimise lateral drift. The fins perform particularly well in winds of up to twelve knots, only slowing down noticeably in stronger winds. However, most inflatable SUPs have long since reached their natural speed limit.