Abstract: The invention relates to the new structure of the fin or the fin's blade (2). The blade (2) is made of segments (S) and transitions (T), wherein a segment with a positive incline and a segment with a negative incline alternate along the blade (2). For example, two neighbouring segments (S) with a transition (T) can form the shape of a wave, a triangle, a trapezium or a tooth. Individual segments (S) can be flat, mainly flat or curved. The lengths of two neighbouring segments (S) with a transition (T) define total length (L). Heights (H) of segments (S), total length (L) and transition (T) length can be equal, they can increase or decrease linearly, progressively or regressively. Random combinations of changing shapes, heights (H), segments (S), total lengths (L) and transitions (T) along the blade (2) are possible. Segments can follow each other across the entire width of the blade's (2) surface or optionally in one part of the fin.

Abstract: The invention relates to the new structure of the fin or the fin's blade (2). The blade (2) is made of segments (S) and transitions (T), wherein a segment with a positive incline and a segment with a negative incline alternate along the blade (2). For example, two neighbouring segments (S) with a transition (T) can form the shape of a wave, a triangle, a trapezium or a tooth. Individual segments (S) can be flat, mainly flat or curved. The lengths of two neighbouring segments (S) with a transition (T) define total length (L). Heights (H) of segments (S), total length (L) and transition (T) length can be equal, they can increase or decrease linearly, progressively or regressively. Random combinations of changing shapes, heights (H), segments (S), total lengths (L) and transitions (T) along the blade (2) are possible. Segments can follow each other across the entire width of the blade's (2) surface or optionally in one part of the fin.

Abstract: Rubbers-gun for underwater fishing, comprising a shaft provided at the front with a head and at the rear with a body with a grip and provided with means for retaining and releasing a spear in which the shaft of the gun is made of polyamide reinforced with glass fibres by means of a gas injection moulding process. The cross-section profile of the shaft of the gun is rhomboid, tapered from the centre towards the two ends. The gun also comprises a reel connected to the said body by means that permit an initial positioning of it horizontally to the said shaft, therefore with the axis of rotation substantially perpendicular to the shaft, and a second positioning inclined at a certain angle compared with the said shaft.