Motor launch (naval)

A WW I motor launch - ML 59
Class overview
Builders	Elco
Operators	Royal Navy
Built	1915–1918
In commission	1915–1920s
Completed	580
General characteristics ML.1–50 series
Type	Motor launch
Displacement	34 t
Length	75 ft (23 m)
Propulsion	Petrol engine
Speed	19 kn (35 km/h)
Complement	8
Armament	1 × 13-pdr later replaced with 1 × 3-pdr depth charges
General characteristics ML.51–550 series
Type	Motor launch
Displacement	37 t
Length	86 ft (26 m)
Propulsion	Petrol engine
Speed	19 kn (35 km/h)
Complement	6
Armament	1 × 13-pdr later replaced with 1 × 3-pdr depth charges
General characteristics ML.551–580
Type	Motor launch
Displacement	37 t
Length	80 ft (24 m)
Speed	19 kn (35 km/h)
Complement	8
Armament	1 × 13-pdr gun later replaced with 1 × 3-pdr

A motor launch (ML) is a small military vessel in Royal Navy service. It was designed for harbour defence and submarine chasing. Similar vessels were used by the Royal Air Force for armed high-speed air-sea rescue. Some vessels for water police service are also known as motor launches. Motor launches were slower than motor torpedo boats and motor gun boats