Shoe-like fin with a short blade made from 100% natural rubber. This material is highly resistant to breakage and abrasion, making it suitable for use by children both in the sea and in swimming pools. The fin is designed so that the shoe is positioned in the middle of the blade, allowing for effective power transfer, with a progressive and comfortable movement for the swimmer, thereby reducing the hydrodynamic resistance of the upper part of the foot. The sole has a stiffness calculated to prevent pinching. The back of the shoe is thicker, reinforced, and features a tongue that makes it easier to put on. All edges that come into contact with the skin are rounded to enhance comfort. The very soft and comfortable elastomer (thermoplastic rubber) that envelops the upper part of the shoe and the side panels promotes the stability of the fin while swimming.