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Martin P5M Marlin

Maritime Service Flying Boat Aircraft

Martin P5M Marlin

Maritime Service Flying Boat Aircraft


Martin P5M flying boats served both the French and American navies, the aircraft line formally retired in 1967.
National Flag Graphic
ORIGIN: United States
YEAR: 1952
STATUS: Retired, Out-of-Service
MANUFACTURER(S): Glenn L. Martin Company - USA
OPERATORS: France; United States

Unless otherwise noted the presented statistics below pertain to the Martin P5M Marlin model. Common measurements, and their respective conversions, are shown when possible.
CREW: 11
LENGTH: 100.72 feet (30.7 meters)
WIDTH: 117.13 feet (35.7 meters)
HEIGHT: 32.81 feet (10 meters)
WEIGHT (EMPTY): 50,486 pounds (22,900 kilograms)
WEIGHT (MTOW): 85,098 pounds (38,600 kilograms)
ENGINE: 2 x Wright R-3350-32WA radial piston engines developing 3,450 horsepower each.
SPEED (MAX): 252 miles-per-hour (405 kilometers-per-hour; 219 knots)
RANGE: 2,051 miles (3,300 kilometers; 1,782 nautical miles)
CEILING: 23,950 feet (7,300 meters; 4.54 miles)
RATE-OF-CLIMB: 1,200 feet-per-minute (366 meters-per-minute)


Up to 8,640lb of conventional or nuclear stores from torpedoes to bombs and depth charges to naval mines.
Graphical image of an aircraft aerial torpedo
Graphical image of an air launched nuclear weapon
Graphical image of an aircraft conventional drop bomb munition

Series Model Variants
• P5M - Base Series Designation
• XP5M - Prototype
• P5M-1 (P5A) - Initial production model; 160 completed.
• P5M-1G (P5M-1T) - P5M-1 for USCG service
• P5M-1S (SP-5A) - Upgraded electronics; improved submarine hunting equipment; 80 conversion examples.
• P5M-1T - USN crew trainers (former USCG mounts).
• P5M-2 (P5B) - Upgraded variant; T-style tail unit.
• P5M-2S (SP-5B) - Improved submarine hunters
• P5M-2G - P5M-2 models for USCG service; 4 examples.
• P5M-3 - Proposed prototype Model 313 aircraft with turbojet installation.
• P-5A - 1962 redesignation of P5M-1
• SP-5A - 1962 redesignation of P5M-1S
• TP-5A - 1962 redesignation of P5M-1T
• P-5B - 1962 redesignation of P5M-2
• SP-5B - 1962 redesignation of P5M-2S


Detailing the development and operational history of the Martin P5M Marlin Maritime Service Flying Boat Aircraft.  Entry last updated on 2/20/2018. Authored by Staff Writer. Content ©
World War 2 showcased the value of large flying boats in the long range maritime patrol and anti-shipping roles. The Glenn L. Martin Company, established in 1912, had been building aircraft for some time before the Second World War and it sold various global military services on its PBM "Mariner" flying boat design which appeared in 1940. 1,285 of this aircraft were produced with the last retired from Uruguayan service in 1964. In the post-war years, Martin tried its hand at a modernized version of its Mariner which went on to become the P5M "Marlin" (Model 237). An improvement overall, the aircraft was procured in just 285 examples by the USN/USCG and the French Navy.

Design experience produced an elegant flying boat through smooth lines and an aerodynamically refined form. The aircraft carried the usual boat-like hull seen in others of this class. Other traditional features were also retained - the high-mounted wing mainplanes, leading edge engine nacelles, outboard wing pontoon floats. The cockpit sat high in the fuselage for good vision out-of-the-cockpit. There were two engines - Wright R-3350 radials of 3,450 horsepower - fitted to streamlined nacelles. A single vertical tail fin was used with low-set horizontal planes. In its original form, the aircraft carried cannon-armed turrets at both the nose and tail sections for defense and a 2 x 0.50 caliber heavy machine gun dorsal turret emplacement.

First flight of an XP5M prototype was recorded on May 30th, 1948.

The aircraft was adopted by the USN/USCG as the P5M-1 and an initial order was for 167 examples. By this time, the finalized aircraft was revised some from its prototype days - most notably was the deletion of the nose cannon turret (replaced by AN/APS-44 series radar under a cone assembly) and dorsal turret, introduction of a raised cockpit flight deck for improved vision, and extended engine nacelles. Production of this form began in 1951 with formal service introduction occurring in 1952.

Martin engineers were not done with evolving their Marlin design. The P5M-2 variant appeared in 116 examples with the most obvious difference being the switch to a "T" tail configuration which set the horizontal planes high atop the vertical tail fin. The tail turret was also deleted and an AN/ASQ-8 MAD ("Magnetic Anomaly Detector") boom assembly added. Other equipment added included the AN/APN-122 DNS ("Doppler Navigation Set"). The lines of the hull were also redrawn form better water performance.

While the USCG was an initial recipient of the Marlin (to be used in the SAR role), the aircraft did not live up to the requirements of the service which led to some eleven machines being passed on to the USN which reconstituted them as training platforms under the TP-5A designation. Original USCG designations were P5M-1G (seven examples) and P5M-2G (four examples). From the period of 1957 to 1959, the French Navy borrowed (and returned) at least ten USN P5Ms for service over Senegal.

P5M Marlins served during the Vietnam War (1955-1975) with the United States Navy where they undertook maritime patrol and surveillance missions in an attempt to stem the tide of supplies reaching the enemy by water. Operations were flown into the late 1960s.

Martin P5M Marlin (Cont'd)

Maritime Service Flying Boat Aircraft

Martin P5M Marlin (Cont'd)

Maritime Service Flying Boat Aircraft

In 1962, the United States military revised its aircraft designation system which resulted in the P5M-1 becoming the "P-5A" and the P5M-2 becoming the "P-5B". The other variants followed suit (see variants listing for full breakdown).

The P5M-2S mark were upgraded P5M-2Ss outfitted with Anti-Submarine Warfare (ASW) equipment and upgraded electronics. The P5M-3 (Model 313) was a proposed flying boat of 1956 fitted with a turbojet engine. It competed unsuccessfully with a Lockheed proposal which went on to become the P-3 "Orion" series.

Many of the Marlin production stock were scrapped after their flying days were over. The only known preserved examples resides at the National Naval Aviation Museum in Pensacola, Florida, USA. The aircraft in question made a tribute flight to USN flying boat operations on November 6, 1967 when it flew over Naval Air Station (NAS) North Island and landed on the waters of San Diego Bay.


Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

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Relative Maximum Speed Rating
Hi: 300mph
Lo: 150mph
    This entry's maximum listed speed (252mph).

    Graph average of 225 miles-per-hour.
City-to-City Ranges
Graph showcases the Martin P5M Marlin's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
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Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units

  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.

Altitude Visualization
Small airplane graphic
Supported Roles
Ground Attack
Aerial Tanker
A2A=Air-to-Air; UAV=Unmanned; CAS=Close Support; ASW=Anti-Submarine; AEW=Airborne Early Warning; MEDEVAC=Medical Evac; EW=Electronic Warfare; SAR=Search-Rescue
Commitments / Honors
Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon representing modern aircraft
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur War
Military lapel ribbon for experimental x-plane aircraft
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.

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