A jack up crane vessel is a specialised vessel for installing foundations and offshore wind turbines. This special vessel’s main features are a heavy lift crane with a load handling capacity of 300 to 1,500 tonnes and a jacking system that enables the crane vessel to carry out tasks regardless of swells. Other features include a large deck surface, tall superstructures to house crew and fitters and a helicopter landing deck (helipad). Moreover, they are fitted with dynamic positioning (DP) systems that enable the installation vessel to use GPS to keep its position at each construction site without external help. Installation vessels these days are around 130 m long and 40 m wide. Using its jacking system with legs, this type of vessel can work in water depths of 45 meters and more.