Watersport board fins with fin retention systems and watersport boards containing the same

A fin to be selectively and operatively coupled to a watersport board, the fin comprising:

• a fin base that is configured to be at least partially received within the watersport board when the fin is operatively coupled to the watersport board;
• a hydrodynamic blade extending from the fin base and configured to extend into a body of water when the fin is operatively coupled to the watersport board and when the watersport board operates upon the body of water;
• a retainer configured to transition between a locked position, in which the fin base is restricted from removal or insertion into the watersport board, and an unlocked position, in which the fin base can be removed from or inserted into the watersport board;
• and
• an actuator configured to transition the retainer between the locked position and the unlocked position, wherein an edge of the actuator is aligned with an edge of the hydrodynamic blade when the retainer is in the locked position, such that the edge of the actuator and the edge of the hydrodynamic blade form a single edge.

A fin to be selectively and operatively coupled to a watersport board, the fin comprising:

• a fin base that is configured to be at least partially received within the watersport board when the fin is operatively coupled to the watersport board;
• a hydrodynamic blade that extends from the fin base and that is configured to extend into a body of water when the fin is operatively coupled to the watersport board and when the watersport board operates upon the body of water;
• a retainer configured to transition between a locked position, in which the fin base is restricted from removal or insertion into the watersport board, and an unlocked position, in which the fin base can be removed from or inserted into the watersport board;
• an actuator configured to transition the retainer between the locked position and unlocked position;
• and
• an actuator recess in the hydrodynamic blade, the actuator being configured to be at least partially received within the actuator recess to transition the retainer from the unlocked position to the locked position.