Abstract: A fin module for a surfboard having a bore extending through the core between the top deck and the underside, including: a fin comprising a core and extending base portion, and a cover forming a fin blade made of resilient material; and a fin box having a cavity for receiving the base portion and adapted to receive an engagement end of a connector having a head anchorable at the top deck and an elongate member extendable through the core of the surfboard to pull the fin box toward the connector head.

Abstract: The present invention relates to a fin box adapted to be fitted to a watercraft and to receive a fin having a base. The fin box includes an elongate receiving portion having a length. The base is adapted to be inserted into the receiving portion substantially laterally. The fin during insertion into the receiving portion is disposed at a lower than 90 degree angle to the receiving portion.

Abstract: A fin collar including a body having a proximal region locatable adjacent to an underside of a water craft. The fin collar also including a distal region, the body including a longitudinally extending slot adapted to receive a watercraft fin, the slot extending through the body between the proximal and distal regions. An outer surface of the body includes a fluid flow modification surface which extends around a perimeter of the body.

Abstract: A fin module (10) for a surfboard (8) having a bore extending through the core between the top deck and the underside, including: a fin (12) comprising a core (18) and extending base portion (14), and a cover forming a fin blade (16) made of resilient material; and a fin box (20) having a cavity (24) for receiving the base portion (14) and adapted to receive an engagement end (32) of a connector (40) having a head (36) anchorable at the top deck and an elongate member (42) extendable through the core of the surfboard (8) to pull the fin box (20) toward the connector head (36).

Abstract: The present invention relates to a fin box adapted to be fitted to a watercraft and to receive a fin having a base. The fin box includes an elongate receiving portion having a length. The base is adapted to be inserted into the receiving portion substantially laterally. The fin during insertion into the receiving portion is disposed at a lower than 90 degree angle to the receiving portion.

Abstract: The invention provides in a first aspect a closure (10) for a passageway such as a bottleneck. The closure (10) has a concertina element (16). When the concertina element (16) is released, the closure (10) can be removed from the passageway. The concertina element (16) may have folds (18), including compressible folds, may be in the form of a spiral. In a further aspect, the invention provides a closure (110), which has processing means (132). The processing means (132), which may include a computer chip (134), is adapted to receive or convey various types of data, such as characteristics of the contents of the container closed by the closure (10). The first and second aspects may be combined.