I'm an avid scuba diver. Ever the domain of the wealthy, scuba diving required both access to the ocean and a shite ton of money for travel & equipment. Not really having any of it, this awesome hobby just kinda passed me by.
The Ju Stuka dive bomber. It was the scourge of the Battle of France but suffered terrible casualties in the Battle of Britain. So much so that after August 1940 it was withdrawn from the battle entirely.