An Italian company, Twin Disc Technodrive have three classifications for their products:-
Pleasure Craft – Intermittent operation with very large variation in engine speed. Maximum power capacity is intended only for personal use, planing hull craft where full engine throttle operation will be less than 10% of the total time with balance of time at 80% of full throttle engine RPM or less. Annual operating hours up to 500.
Intermediate Duty – Full throttle operation will average only a few hours per day with major portion of usage at partial throttle and total annual usage of 2000 hours or less.
Continuous Duty – Continued operation with full engine governed speed. Unlimited hours per year.