Pneumatic or hydraulic gyroscopes measure a boat’s roll, but they don’t orient themselves to the horizon. They also don’t sense the velocity of roll. New electronic controllers do, and can be retrofitted to an older system.
By electronically sensing angle to the horizon as well as the velocity and acceleration of roll, Naiad Dynamics DATUM and MultiSea II electronic controllers compensate more effectively for waves, particularly the long, slow roll associated with a large following swell. Naiad also incorporates GPS boat speed in system calculations, allowing larger fins for slower speed yet reducing the angle of attack at higher speed. Upgrading a hydraulic gyro to an electronic controller runs around $25,000 plus the cost to modify or replace existing, smaller fins.
Gyro-Gale also offers an electronic control upgrade for around $7000, as well as a two-piece articulating fin designed to add lift much like the flaps of an aircraft wing. New fins for a typical 80-footer cost around $20,000, available with or without the electronic upgrade.
To view historic photos of a gyrostabilizer built in 1916, click here.