I've been wondering when dive watches made the change from bidirectional smooth to unidirectional click-type rotational movement. Most vintage dive watches I've come across have biredctional, smooth rotating bezels. For example, I own a 1969 Bulova Snorkel Oceanographer and 1975 Caravelle 666 foot dive watch. Both bezels move clockwise and counter clockwise.
Perhaps this was more a function of individual manufacturers, with higher end dive watches like Rolex and Omega having unidirectional from their beginning.
I think most manufacturers realized at some point that there is greater potential for error in a bi-directional bezel that turns smoothly if it were to snag on a wetsuit . This could of course be a hazard to divers watching their dive time.
Anyone know when the transition to unidirectional bezels was made in most dive watches?