An analysing device and method for analysing a submerged net

The present disclosure describes a subsea assembly (100) for imaging and cleaning a submerged net (130), the subsea assembly (100) comprising a first subsea unit (110) for being positioned on a first side of the net (130), the first subsea unit (110) comprising at least two parallelly oriented belt assemblies, and a camera (200), a second subsea unit (120) for being positioned on a second side of the net (130) opposite to the first subsea unit (110), the second subsea unit (120) comprising at least two parallelly oriented belt assemblies (150), and a background element (240), where the first subsea unit (110) and/or the second subsea unit (120) further comprises a cleaning means (140) for cleaning the net (130), where each belt assembly (150) comprises a track (160) provided with magnets for generating an attractive force between the belt assemblies (150) of the first subsea unit (110) and the belt assemblies (150) of the second subsea unit (120) such that the subsea assembly (100) adhere to the net (130), and where the camera (200) and the background element (240) are arranged such that they face each other when the subsea assembly (100) adhere to the net (130). The present disclosure also describes use of a subsea assembly (100) and a method for imaging and cleaning a submerged net (130) of a fish pen.