Propeller-powered underwater vehicles have long helped scientists explore and monitor aquatic environments. But they’re limited by their own mechanics: Spinning blades can snag on vegetation, stir up sediment and startle the wildlife they’re often sent to study, making them poorly suited to shallow creeks, dense weeds or close encounters with fish.Propeller-powered underwater vehicles have long helped scientists explore and monitor aquatic environments. But they’re limited by their own mechanics: Spinning blades can snag on vegetation, stir up sediment and startle the wildlife they’re often sent to study, making them poorly suited to shallow creeks, dense weeds or close encounters with fish.[#item_full_content]