Possible Clues:

• A ship at first for high rank on land
• Army officer shortly becoming part of old navy?
• Try to cheat in game held by brother officer?
• Wrong container for engineer - item, oddly enough, right for officer
• A ship with a buck, by the sound of it, for high rank
• Gerard, who duelled with Mill Reef
• He ranks with Doyle's Gerard
• Arrange announcement during last stand of officer
• Officer making vessel stop running in a river
• Officer who would make brief appearance in British outfit