As far as booking on another line, I could do that, but unfortuantely I am going to be onboard as the result of a gift trip to Bermuda. Somebody else has booked and paid for the trip for me. It would be more rude for me to turn down the passage which has been bought and paid for by somebody else.
So you think that it's less rude to embarass the "somebody else" who has paid for your cruise by ignoring the prescribed dress than by turning down the cruise in the first place?
If that's your attitude, I really will stand by my original choice of adjectives!