Patent ID: 7115011

Claim:
An improved swim fin, comprising: a foot-packet formation formed with a foot-receiving cavity; and a fin blade attached and extending longitudinally beyond the foot-packet formation to a trailing edge thereof for a first length, said fin blade having an imaginary center line splitting down the middle of the fin blade and extending longitudinally so as to substantially separate the fin blade into two portions, said fin blade further comprising: at least a first movable member disposed on one of the two portions of the fin blade, the first movable member is triangular shaped and is defined by a first longitudinal edge, a first leading edge and a first connecting edge, the first longitudinal edge being located in a vicinity of the center line and being substantially extending parallel to the center line, the first leading edge being located near to but spaced apart from the trailing edge by a first distance, the first longitudinal edge and the first leading edge both being through slots and being connected to each other at one end thereof, the first connecting edge being an imaginary connecting line with one end connected to the first longitudinal edge and the other end connected to the first leading edge so as to form the triangular shaped first movable member; and at least a second movable member disposed on another portion of the fin blade, the second movable member is triangular shaped and is defined by a second longitudinal edge, a second leading edge and a second connecting edge, the second longitudinal edge being located in a vicinity of the center line and being substantially extending parallel to the center line, the second leading edge being located near to but spaced apart from the trailing edge by a second distance, the second longitudinal edge and the second leading edge both being through slots and being connected to each other at one end thereof, the second connecting edge being an imaginary connecting line with one end connected to the second longitudinal edge and the other end connected to the second leading edge so as to form the triangular shaped second movable member; wherein, the fin blade further comprises two openings and two side ribs, each of the two openings is formed on an outer edge of the fin blade for inserting one side rib in a removable manner; and, wherein, when the side ribs are inserted in the openings, structural strength of the fin blade is increased; when the side ribs are removed from the openings, the fin blade is still functional for swim fin operation but in a more flexible manner.