Watercraft fin

A fin for a watercraft comprising:

• a substantially planar member having a first side surface, a leading edge, a second side surface opposite the first side surface, a trailing edge opposite the leading edge, and a base providing an area for attachment to a watercraft surface by either mechanical means or permanent bonding, wherein the leading edge and the trailing edge intersect at a fin tip;
• at least one flexible spine having an elongate body with a length, a top side, a bottom side, a first end spaced apart from a second end and peripheral edges joining the top and bottom sides such that a spine width associated with at least the top side is greater than a spine thickness associated with the peripheral edges, each flexible spine is molded from a composition of a plurality of unidirectional fibres and resin using a continuous pultrusion molding process;
• and
• wherein the at least one flexible spine is bonded to be fixed between the first and second side surfaces of the fin;
• wherein the plurality of unidirectional fibres form an elastically deformable spine;
• and
• wherein the composition of fibres and resin, number, placement and size of the at least one flexible spine between the first and second side surfaces of the fin, provides the fin with a customised dynamic flex pattern, strength properties, a controlled rate at which the fin vibrates and a dampening effect which reduces a recoil rate of the fin when an applied force is removed from the fin and allows the fin to return to an original shape.