I think we have all seen the " connoisseurs " of wine on cruises and in restaurants. And no doubt, there are people who are expert enough in the field to tell the difference between fine wines, etc.
However, on the average cruise ship and the average passenger who orders a bottle of wine at dinner and goes through the motion of swirling, sniffing, tasting and then always giving the nod that it's ok, I think most of these folks are " experts " in their own mind. I don't believe I can really remember seeing anyone actually send a bottle back after going through the motions.
You can watch a person go through the ritual and observe how they do it to see if they are halfway qualified to know whether or not it's a good wine--the glass should be left on the table--with the fingers on the flat part of the stem, swirled slightly, then lifted by the stem to run the nose into the glass,aka sniffing -- then when it's tasted and or consumed, the fingers should not hold the glass, but the stem, as the warmth from the hand around the glass can alter the taste---according to the experts !
No, I'm not a connoisseur of wine-- I believe in the old saying-- you drink what you like--if you are having fish and you like red wine, and you're paying, who's to say it's not ok?? Personally, I like water with lemon--that way I don't have to swirl, sniff, taste, nod my head it's ok and then hold the glass by the very bottom so as to not warm my ice water !