A mooring system (28) of a floatable unit (20), such as life raft or platform, the floatable unit (20) having a first side (21) facing a vessel side (22) and a second side (23) facing away from the vessel side (22). The mooring system (28) comprises at least two back springs (2) which are in connection with the first side (21) of the floatable unit (20), and at least one strap (1) which is in connection with the second side (23) of the floatable unit (20), the back springs (2) and the strap (1) being connected to the vessel (30). The back springs (2) are adapted to control the floatable unit (20) in a longitudinal direction in relation to the vessel (30), and the strap (1) is adapted to control the floatable unit (20) in a transverse direction in relation to the vessel (30). The floatable unit is held in secure and fixed position alongside the vessel side, thereby enabling people evacuating from the vessel to enter the floatable unit without any high risk of injury or damage.