relatively limited forces are required for raising by means of a spindle application_number US 82107786 A description the yacht shown in fig1 has a lifting keel 1 whose upper area 2 is guided in a lifting keel box 3 in the represented embodiment there are two spiral springs 4 acting as tensioning elements in the lifting keel box 3 but only the right hand spring is visible the spiral springs 4 run from the top of the cabin 5 where the lifting keel box 3 ends to the lower end 6 of the lifting keel 1 at the centre of gravity of lifting keel 1 there is a spindle 7 which is fixed in rotary manner in the vicinity of the cabin top or roof 5 at its lower end 8 it engages on the lifting keel 1 in a corresponding thread or the like on turning spindle 7 it is possible to raise the lifting keel 1 or lower it into the position shown here fig1 shows the lifting keel 1 completely lowered the spiral springs 4 being under maximum tension the total force acting on lifting keel 1 as a result of the two spiral springs 4 can correspond to the weight of said keel less the buoyancy caused by the water spindle 7 can easily be operated by hand e g by means of a.