While the missile worked against Second World War-era level flying targets, the beam guidance system was dubious at range and in rough water which meant eight fixed stabilisers were added to the design of the County-class. Advocacy for the guided missiles fit was led by Mountbatten and the Cabinet agreed with using the system, despite staff reports over missile unreliability and inaccuracy, confirmed by the dismal performance in the following 1959 Seaslug target launches at Woomera in South Australia. Many Royal Australian Navy officers felt Seaslug was unsuitable for the RAN.