Swimming assistance accessory, especially for performing a stroke requiring an undulatory movement

A swimming assistance accessory, comprising:

• a body forming a lower part of the accessory designed to be immersed during a stroke;
• a holder configured to hold the accessory adapted to a swimmer's two-handed grip, both hands to be partly overlapped, the holder extending on an upper part of the body, said upper part of the body forming a leaning area;
• a float enabling water to exert, on the accessory, a vertical force resulting from the buoyant force opposed to gravity, and
• wherein a plane forming a vertical plane of symmetry of the accessory comprises a center of gravity of the accessory and a center of gravity of the ballast.

A swimming assistance system comprising

• a swimming assistance accessory comprising
• a holder configured to hold the accessory during a stroke adapted to a two-handed grip;
• a float enabling water to exert, on the accessory, a vertical force resulting from a buoyant force opposed to gravity;
• a body comprising a ballast for holding a barycenter of the holder substantially under the water surface when the accessory is in a balance position in water,
• wherein the holder forms a junction between the body and the float, an upper part of the body comprising the ballast forming a leaning area for swimmer's hands, and
• a ballast belt enabling the swimmer to keep the balance position of the accessory when he/she holds it at his/her arm's length.