The invention provides an object (10) that during use is at least partly submerged in water, the object (10) further comprising an anti-biofouling system (200) comprising an UV emitting element (210), wherein the UV emitting element (210) is configured to irradiate with UV radiation (221) during an irradiation stage one or more of (i) a part (111) of an external surface (11) of said object (10) and (ii) water adjacent to said part (111) of said external surface (11), wherein the light source (220) is at least controllable between a first UV radiation level and a second UV radiation level, wherein the first UV radiation level is larger than the second UV radiation level, wherein the object (10) is selected from the group consisting of a vessel (1) and an infrastructural object (15), wherein the object (10) further comprises a control system (300) configured to control said UV radiation (221) as function of input information comprising information of one or more of (i) a location of the object (10), (ii) movement of the object (10), (iii) a distance (d) of the object (10) to a second object (20), and (iv) a position of the part (111) of the external surface (11) relative to the water.
