20 Things You Didn't Know About Diamonds Are Forever (1971)
13. “Prepare My Bathosub Immediately!”
Charles Gray’s Ernst Stavro Blofeld has a “bathosub” mini-submarine emblazoned with SPECTRE’s octopus emblem so that he can flee from his oil rig lair (without his white Persian cat) when the going gets tough, but his escape plan proves to be his undoing.
Taking control of the crane lowering the bathosub into the ocean, Double-0 Seven uses it as a battering ram to destroy the rig’s control room and disable Blofeld’s laser satellite.
Car customiser, George Barris - who had previously provided such memorable cars for both television and films as The Munster’s Koach and Adam West’s Batmobile - built two versions of the bathosub to Ken Adam's specifications.
The first was filled with concrete so that it could be used as a makeshift wrecking ball. The second was designed for Charles Gray to climb into and was equipped with a control panel that made it look as though it was a real vehicle, even though neither bathosub was functional.
The first bathosub was scrapped shortly after filming was completed, but the second survives to this day and regularly appears at James Bond-related events and exhibitions.