The Navy’s last Marlin — Martin P5M walkaround

The Navy’s last Marlin — Martin P5M walkaround

30º 21′  03″ N / 87º 18′ 13″ W

The Martin P5M-2 Marlin (later called SP-5B) at the National Naval Aviation Museum — photo by Joe May

Starboard side of the Marlin, note the large searchlight suspended from the wing’s tip — photo by Joe May

Martin’s last design in a long history of flying boats was the P5M Marlin, later redesignated to the SP-5 Marlin. She served for nearly two decades from 1951 through the 1960s, flying missions in the Vietnam War aiding in the detection and  tracking of military shipping from North Vietnam to South Vietnam. Carrying a crew of eleven the Marlin was equipped with a searchlight mounted on its starboard wing as well as radar and magnetic anomaly detection (MAD) equipment. Two radial engines gave her an impressive 6900 hp (5140kW) and they were set high off the water with the aid of the gull wing design feature. Weapons bays were incorporated into the engine nacelles while the nose and tail gun turrets were eliminated after the initial Marlin model. The T-tail is also unusual with its dihedral horizontal stabilizer.

The Marlin’s empennage, note the MAD extension from the vertical stabilizer as well as the dihedral of the port side horizontal stabilizer — photo by Joe May

The Marlin’s bows and gull wing design — photo by Joe May

The Marlin is a direct descendant of the Martin PBM Mariner. Frankly, the Mariner had a checkered reputation due to fuel vapor accumulating in the bilge spaces. Having high octane gasoline vapors hanging about with all the electrical equipment in a large military search aircraft is not a recipe for reaching retirement age. But the Marlin’s family tree reaches back to WW II and, what may seem incredible, Japan’s firm Kawanishi and what may have been WW II’s best flying boat, the Kawanishi H8K2 二式大型飛行艇 二式大艇 (Allied codename Emily). The influence can is seen in the aft portion of the fuselage rising gradually from the step instead of sharply. This feature is credited with significantly reducing the porpoising that could occur while on the waves.

The P5M’s radome, cockpit and handling line and note the four portholes — photo by Joe May

The rare example left to us, formerly a P5M-2 but renamed SP-5B, has been restored with a mint condition exterior and is on exhibit in at the National Naval Aviation Museum. This Marlin flew her last mission in 1967 and was repaired and restored after damage from Hurricane Ivan in 2007. Restoration was largely accomplished through the efforts of the Mariner/Marlin Association and what a restoration! This Marlin looks ready to take to the water and her way over the ocean waves.

Forward section of the P5M Marlin — photo by Joe May

Something that caught my eye were the tanks on the beaching gear. I assume these tanks aiding in attaching or detaching the beaching gear, as the Marlin is a flying boat and not amphibious, with their buoyancy. The detail to note is the port tank is red and the starboard side green, which mimics the navigation light colors for those respective sides.

Aviation historian Bruce D. Barth has an excellent website on the PBM Mariner and P5M Marlin and provided information for the post, as well as the above mentioned references.

The post of the museum, and others about its aircraft, can be found by entering the name into the search window (which will take you the blog’s WordPress site) and selecting ENTER.

Similarly, a post of the rare Kawanishi Emily can be found by pasting “Emily” into the search window and selecting ENTER.