When 'Double Century'?the 656-foot superyacht being built for three-quarters of a billion dollars?is finished, it'll be the world's biggest. And even it won't have trouble docking in Porto Montenegro's humongous new 820-foot superyacht berth, the world's longest.

The second week in July, this luxurious Adriatic hotspot will play host to their second annual Superyacht Rendevous.