Fin

A fin to be attached to a fin attachment groove formed in a bottom surface of a surfboard, the fin comprising:

• an attachment base portion sized and configured to be received within the fin attachment groove in the bottom surface of the surfboard;
• a plurality of hollow parts formed within at least one side surface of the attachment base portion of the fin,
• at least one plunger positioned within a first respective one of the hollow parts, the plunger comprising a ball part and an elastic member which biases the ball part outwardly of the hollow part for engagement with a first corresponding opposed surface portion of the groove when the attachment base portion is received therein so as to provide detachable mounting of the fin to the surfboard;
• and
• at least one non-slip member positioned within a second respective one of the hollow parts, the non-slip member comprising a main body portion sized and configured to be received within the hollow part, and a non-slip part at an exposed end face of the main body portion, wherein the non-slip part protrudes outwardly from the hollow part so to be sandwiched between the attachment base portion and the groove, the non-slip part being engaged with a second corresponding opposed surface portion of the groove when the attachment base portion is received therein, wherein the non-slip member is formed of a resin material providing frictional resistance with the second corresponding opposed surface portion of the groove against which the non-slip member is engaged so as to prevent fin rattling when the attachment base portion is detachably mounted to the fin attachment groove of the surfboard.