I have absolutely no problems with non British captains. Indeed, I believe that I have already been taken places on QE2 by at least one non British captain, i.e. Nick Bates.
Not being British does not, of course, mean that one cannot speak English. Most Irish, American, Australian, and New Zealand people speak an English of (their own) sorts, as do most Indians, Pakistanis, Bangaldeshis, Maltese, South Africans and Kenyans, to name but a few countries. Of course, on a "British" (and is Cunard really British nowadays...?) ship, a perfect mastery of English must be a prerequisite for a Captain who is expected to mix and mingle graciously with the mostly English-speaking passengers. But one does not even have to be a citizen of a former British colony to achieve this feat!
To return to matters a bit more practical, last year on Black Prince, I was delighted to find that several of the deck crew who had quite possibly started at the lowest entry grades, had progressed up the careers ladder and their photographs were hung quite close to the (Norwegian -- a perfect English speaker too) Captain on the notice board showing us who was who on the ship. I would find it rather offputting if nationality was used as grounds for refusing deserved promotion to hard working and committed crew. It goes without saying, of course, that people should only be promoted to their positions if adequately qualified and experienced.
Indeed, they could even be.... women....

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