The atmosphere at mid-February’s Miami International Boat Show, which displayed more than 3,000 boats, was the most positive it has been in years. Despite Valentine’s Day storms that canceled thousands of flights and left many would-be showgoers stuck in the Midwest and Northeast, visitors from the rest of the United States, Latin America, and Europe flew in to investigate dozens of new models and walk the docks. For the first time since before the onset of the global recession, boatbuilders and yacht brokers …