Here’s a strange thing. Despite spending much of my life living by the sea – I grew up in beautiful Salcombe, in Devon – most of my boating experience (apart from the odd ferry to France, or between Thai islands) has been on little ships that pootled around the estuary. I’d see some sizeable yachts sail past my hometown, but sadly never got the chance to experience some of this opulence first-hand.   Now, though, I scoff at these titchy gin palaces with their limited sailing range and glaring absence of on-board nightclubs and Vegas-level entertainment shows, because I’ve jumped straight to the top of the big ship league table…