The seaglider hybrid vehicle begins sea trials in Narragansett Bay, Rhode IslandAmory Ross / REGENTAn all-electric seaglider that can transition between floating and flying has begun sea trials in Narragansett Bay, Rhode Island. The tests are a prelude to the vehicles first crewed flights, scheduled for later this year, which would make it the largest battery-powered flying machine in the world albeit one that must remain just above the waters surface.Electric aircraft are tricky because they must carry heavy batteries, which