Megasonic was a tuning fork movement from Omega and the CEH.
Swiss inventor Max Hetzel created the Bulova Accutron in 1953, building prototypes in 1955 and participating in the final design for the 1960 launch of Cal. 214. Hetzel left Bulova in 1963 amid disputes with management in New York and returned to Switzerland to work for Ebauches SA. There, he worked with the team developing the Mosaba tuning fork movement, leveraging the Bulova patents which ESA had licensed in 1968.
In 1973, the Centre Electronique Horloger, SSIH, and Omega announced the Megasonic. This was a next-generation tuning fork movement quite different from the Accutron and Swissonic. Where those operated at 360 Hz or 300 Hz, respectively, the Megasonic vibrated at 720 Hz. It used a new micro-motor leveraging an oil-filled capsule with the toothed ratchet wheel. Two ruby pawls on the resonator advance the wheel with each oscillation, and a magnetic coupling is used to connect the sealed system to the wheel train.
The Megasonic was used by Omega starting in 1973 but never reached its potential as quartz movements gained accuracy and popularity. Although the Megasonic was capable of +/- 10 seconds per month accuracy, the production product only boasted +/- 30 seconds, and high-accuracy quartz movements were able to beat this by an order of magnitude. The Omega Megasonic 720 came to market alongside the Megaquartz 2400 and 32 and the Time Computer digital watch, both of which overshadowed it.