Method for establishing a consolidated water current velocity profile

A method for determining a water current velocity profile in a water column by registration of a deviation between a first position and a second position of an underwater vehicle travelling in the water column, said method comprising:

• deploying a first batch of underwater vehicles comprising at least one vehicle from a surface vessel into the water,
• said at least one vehicle steering to the first position which for the first batch is a predefined estimated position (PEP) calculated by a first predefined water current velocity profile wherein the at least one vehicle by first means is recording the second position, which is the actual position (AP),
• the difference ΔP between the predefined estimated position PEP and the actual position (AP) is registered and based on said difference a deviation data set is calculated and an updated horizontal water current velocity UV is determined in said water column,
• the updated water current velocity UV is sent to a controller,
• said controller is updating the predefined estimated position PEP to an updated estimated position UEP based on the predefined estimated position PEP and the updated water current velocity UV, and
• a next batch of vehicles dropped into the water are steering to the first position based on the updated estimated position UEP.