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