Rigid platforms are known in the boating sector on which manual, mostly telescopic extendable ladders are fixed as described in patent EP 1 616 782 A1, in the case of ships extendable steps are used, that run hydraulically and also by the use of a winch as described in patent MXPA 0201 1583, in the case of leisure yachts extendable ladders as well as stairs with horizontal steps are also in use which can be activated hydraulically or electrically. Passengers and animals use these as a convenient way of getting into or out of the water. Large ships also use the stairs as a way for going on land.
The engine driven ladders and stairs are directly integrated in the watercraft or stored in boxes in the swimplatforms and are horizontally fully extentable and can be tilted down towards the water by the use of an articulated joint, as described in patent FR 2878822. In many cases the tilting is effected by an additional cylinder. A combination of a rigid swimplatform and movable stair elements is described in US patent 2006/0075952 A1, whose step elements are tiltable but do not have the safety elements with regard to cutting and bruising. Known are also drop down swimplatforms which can be lowered to below the waterline with the special use for collecting tenders and jetskis as described in, for example, patent DE 199 63 057 C1.