Deep-sea diving suit

The Deep-sea diving suit was a large breathing suit designed by Leonardo da Vinci for underwater exploration.

History
After stealing Leo's Notebook, the suit was built and tested by Piero de' Medici who found it to be effective to a depth of eight fathoms (14.63 metres).

Leonardo was elated to see the suit in person when he visited Piero's workshop. (Fireball)