Abstract: The invention pertains to an arrangement for dynamic control of running trim and list of a boat, having at least one hull with a stern. The arrangement (100) has a housing member (102), an interceptor member (103, 103'), an actuator (105) and a power supply (106). The actuator (105) is arranged for displacing the interceptor member (103, 103') in a continuous linear movement between first (103) and second end positions (103') or vice versa in relation to said housing member (102), which comprises an attachment (104, 104', 104", 104'") for attachment to the hull. The interceptor member (103, 103') has a first portion (107) and a second (108) portion, wherein the first portion (107) extends essentially perpendicularly from the middle of the entire length of the second portion (108). The housing member (102) partially encloses the first portion (107) so that the housing member (102) firmly guides the first portion (107) during the linear movement.