Calling these sails is a stretch, and IMHO just an attempt to market them as more "green" than they really are. They may as well be propellers. It's great to

Calling these sails is a stretch, and IMHO just an attempt to market them as more "green" than they really are. They may as well be propellers. It's great to improve the fuel efficiency of these vessels, but the word sail evokes a mental image profitably inconsistent with reality.