Guest Stars Donald Sumpter as Commander Ridgeway Edwin Richfield as Captain Hart Stanley McGeagh as Castle Guard Drew Pat Gorman as Sea Devil Royston Tickner as Robbins Peter Forbes-Robertson as Chief Sea Devil Martin Boddey as Walker Neil Seiler as Radio Operator Alec Wallis as Ldg. Telegraphist Bowman Brian Justice as Castle Guard Wilson Colin Bell as C.P.O. Summers Eric Mason as C.P.O. Smedley John Caesar as C.P.O. Myers Rex Rowland as A/B Girton June Murphy as 3rd Officer Jane Blythe Terry Walsh as Castle Guard Barclay Christopher Wray as Ldg. Seaman Lovell Norman Atkyns as Rear Admiral Clive Morton as Trenchard Brian Vaughan as Lt. Commander Watts David Griffin as Lt. Commander Mitchell Hugh Futcher as Hickman Declan Mulholland as Clark
