'If we die, we die together.'
Some of the units are advertised as having been 'designed by former Nasa engineers'.
The lightweight robot takes inspiration from diving birds that can both swim and fly (Picture: Raphael Zufferey and Victor Pennacino/Cover Images)
The pilot and two passengers exited the light aircraft safely after crash-landing in the sea.
'They also have a similar density to shaving foam.'
