Guest Stars Donald Sumpter as Commander Ridgeway Martin Boddey as Walker Rex Rowland as A/B Girton Declan Mulholland as Clark Brian Vaughan as Lt. Commander Watts Hugh Futcher as Hickman Royston Tickner as Robbins 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 David Griffin as Lt. Commander Mitchell June Murphy as 3rd Officer Jane Blythe Terry Walsh as Castle Guard Barclay Christopher Wray as Ldg. Seaman Lovell Peter Forbes-Robertson as Chief Sea Devil Norman Atkyns as Rear Admiral Pat Gorman as Sea Devil Stanley McGeagh as Castle Guard Drew Edwin Richfield as Captain Hart Clive Morton as Trenchard
