Removable device allowing stationary swimming in an above-ground swimming pool or self-supporting swimming pool

Device allowing stationary swimming in an above-ground pool or freestanding, comprising: a computer (2) intended to surround the swimmer's body, constituted for example by a belt or harness; a flexible retaining strap (3), fixed or is fixed by one end to said equipment, at least one attachment pole (4) provided at its upper portion, at least one attachment point (5) which allows the attachment of the other end of the retaining strap (3), characterized in that the base of the attachment pole (4) is provided or arranged to be provided removably, at least one plate anchoring base (6) It is extending laterally with respect to the mast (4), this base plate (6) an elongated shape and a size such that a major portion (L) of its length (L) can be slid beneath one of the ends of a water tank (1) resting on the ground (S), so that is firmly blocked by the mass of water contained in said tank, thus ensuring immobilisation and stability of the attachment pole (4) fixed on said base plate (6).