A controllable submersible system, as shown in Figure 1 of the specification, which, in one variant of the system, involves a modified wheelchair which allows its occupant to descend into, and ascend out of, water, and to travel in the water, at various depths, or on the surface of the water. According to the present invention, a wheelchair is provided with means for, i) propulsion in water, whilst at the surface of the water, and whilst at various depths in the water, and ii) for controllable descent into, and controllable ascent out of, water, for various depths. The invention thus represents an alternative way of using a wheelchair via the utilisation of propulsion units which are normally found on conventional diving equipment and on dive propulsion vehicles. One variant of the invention involves apparatus comprising modifications to a basic National Health Service wheelchair in order to allow the fitting of propulsion units and controls therein, and to allow flexible movement, up and down in the water, and in various directions in the water under full control of the occupant of the wheelchair. This allows the performance of aquabatics, at the surface of, and under, water, in the same way that an acrobat performs such movements on land, and an aerobat performs in the air. The occupant of the submersible wheelchair is thus able to perform dance like movements, and to make performances such as loop-the-loop and barrel roles, etc. These performances are referred to as aquabatics, in the same way that acrobatics are performed on land and aerobatics are performed in the air. The invention also allows the equivalent of synchronised swimming to be performed by wheelchair users.La présente invention concerne un système submersible contrôlable, comme présenté sur la figure 1 du mémoire qui, dans une variante du système, est constitué dun fauteuil roulant modifié qui permet à son occupant de simmerger dans leau et den ressortir, de se déplacer dans leau à diverses profond
