Sir, – Commander de Silva’s extensive article [111/3, p. 66] on how we might contemplate a Royal Marine officer becoming First Sea Lord intrigued me. It is not immediately clear to the reader whether any RM actually aspires to be 1SL. That aside, so much has changed in the upper echelons of defence management that anything is possible. In the ‘old days’, when command of ships was more readily available then it is now, it was almost impossible for a commander to be promoted captain without having commanded at sea, or a captain to flag rank similarly. Even warfare specialists such as pilots or s…