One explanation is an old one, MONEY. My understanding is that for a cargo ship of reasonable size, the diesel or black oil fuel to cross the Atlantic can be >

One explanation is an old one, MONEY. My understanding is that for a cargo ship of reasonable size, the diesel or black oil fuel to cross the Atlantic can be > $1 million. The wind? Free. And, with a well designed sailboat, the speed can be reasonably fast. And save on the purchase and maintenance costs of steam turbines and big diesel engines and their weight.