A pivotal fin system, for use with an aquafoil, such as surfboards, body boards,
wave skis, sail boards, wake boards and the like, comprising a pot (3) and
a fin (2), having a tab (18) extending from the base (17)
of the fin (2). The pot (3) has a central slot (11) and is
mounted in the board (23) with the opening of the central slot (11)
flush with the board (23). The slot (11) has a releasable locking
means (6 & 7) therein, and the tab (18) has a connection means
(21 & 22), which is releasably engaged by locking means (6 &
7). Preferably the releasable locking means (6 & 7) is a substantially
c-shaped clamp, and the connection means (21 & 22) has a recess or
recesses (22) behind a bulbous extension (21), which is engaged in
the c-shaped clamp, with arms (5) of the c-shaped clamp engaging in the
recess or recesses (22).
