No.1-class submarine chaser

	(left to right) No. 1, No. 2 and No. 3 in 1938
Class overview
Name	No. 1-class submarine chasers; No. 1 class (Project number K3); No. 3 class (Project number K4);
Builders	Uraga Dock Company; Tōkyō Ishikawajima Shipyard; Asano Shipyard;
Operators	Imperial Japanese Navy
Succeeded by	No. 4 class
Cost	1,525,700 JPY (No. 1-class); 1,530,000 JPY (No. 3-class);
Built	1933 – 1936
In commission	1934 – 1946
Planned	3
Completed	3
Lost	1
Retired	2
General characteristics No. 1-class
Displacement	266 long tons (270 t) standard; 280 long tons (284 t) trial; and after late 1934; 377 long tons (383 t) trial;
Length	65.30 m (214 ft 3 in) overall; 64.00 m (210 ft 0 in) waterline;
Beam	5.90 m (19 ft 4 in)
Draught	1.43 m (4 ft 8 in)
Propulsion	2 × Kampon Mk.22 Model 8 diesels; 2 shafts, 3,400 bhp;
Speed	24.0 knots (27.6 mph; 44.4 km/h); and after late 1934; 21.1 knots (24.3 mph; 39.1 km/h);
Range	1,500 nmi (2,800 km) at 14 kn (16 mph; 26 km/h)
Complement	65
Armament	2 × 40 mm heavy machine guns; 36 × depth charges; 1 × depth charge thrower; 1 × Type 93 active sonar; 1 × MV hydrophone;
General characteristics No. 3-class
Displacement	270 long tons (274 t) standard; 285 long tons (290 t) trial;
Length	56.10 m (184 ft 1 in) overall; 55.00 m (180 ft 5 in) waterline;
Beam	5.60 m (18 ft 4 in)
Draught	2.10 m (6 ft 11 in)
Propulsion	2 × Kampon Mk.22 Model 6 diesels; 2 shafts, 2,500 bhp;
Speed	20.0 knots (23.0 mph; 37.0 km/h)
Range	1,500 nmi (2,800 km) at 14 kn (16 mph; 26 km/h)
Complement	60
Armament	2 × 40 mm heavy machine guns; 36 × depth charges; 2 × Type 94 depth charge projectors; 1 × depth charge thrower; 1 × French SCAM active sonar; 1 × Type 93 hydrophone;

The No. 1-class submarine chaser (第一号型駆潜艇, Dai 1 Gō-gata Kusentei) was a class of submarine chasers of the Imperial Japanese Navy (IJN), serving during World War II. Three vessels were built in 1933-36 under the Maru 1 Programme and the Maru 2 Programme. They have two sub classes.

Class overview
(left to right) No. 1, No. 2 and No. 3 in 1938
Name	No. 1-class submarine chasers No. 1 class (Project number K3) No. 3 class (Project number K4)
Builders	Uraga Dock Company Tōkyō Ishikawajima Shipyard Asano Shipyard
Operators	Imperial Japanese Navy
Succeeded by	No. 4 class
Cost	1,525,700 JPY (No. 1-class) 1,530,000 JPY (No. 3-class)
Built	1933 – 1936
In commission	1934 – 1946
Planned	3
Completed	3
Lost	1
Retired	2
General characteristics No. 1-class
Displacement	266 long tons (270 t) standard 280 long tons (284 t) trial and after late 1934 377 long tons (383 t) trial
Length	65.30 m (214 ft 3 in) overall 64.00 m (210 ft 0 in) waterline
Beam	5.90 m (19 ft 4 in)
Draught	1.43 m (4 ft 8 in)
Propulsion	2 × Kampon Mk.22 Model 8 diesels 2 shafts, 3,400 bhp
Speed	24.0 knots (27.6 mph; 44.4 km/h) and after late 1934 21.1 knots (24.3 mph; 39.1 km/h)
Range	1,500 nmi (2,800 km) at 14 kn (16 mph; 26 km/h)
Complement	65
Armament	2 × 40 mm heavy machine guns 36 × depth charges 1 × depth charge thrower 1 × Type 93 active sonar 1 × MV hydrophone
General characteristics No. 3-class
Displacement	270 long tons (274 t) standard 285 long tons (290 t) trial
Length	56.10 m (184 ft 1 in) overall 55.00 m (180 ft 5 in) waterline
Beam	5.60 m (18 ft 4 in)
Draught	2.10 m (6 ft 11 in)
Propulsion	2 × Kampon Mk.22 Model 6 diesels 2 shafts, 2,500 bhp
Speed	20.0 knots (23.0 mph; 37.0 km/h)
Range	1,500 nmi (2,800 km) at 14 kn (16 mph; 26 km/h)
Complement	60
Armament	2 × 40 mm heavy machine guns 36 × depth charges 2 × Type 94 depth charge projectors 1 × depth charge thrower 1 × French SCAM active sonar 1 × Type 93 hydrophone