
The Consolidated XP4Y Corregidor was an American twin-engined long-range maritime patrol flying boat built by Consolidated Aircraft for the United States Navy. Only one was built and a production order for 200 was cancelled.

The Consolidated PBY Catalina is a flying boat and amphibious aircraft that was produced in the 1930s and 1940s. In Canadian service it was known as the Canso. It was one of the most widely used seaplanes of World War II. Catalinas served with every branch of the United States Armed Forces and in the air forces and navies of many other nations. The last military PBYs served until the 1980s. As of 2014, nearly 80 years after its first flight, the aircraft continues to fly as a waterbomber in aerial firefighting operations in some parts of the world. None remain in military service.

The PB2Y Coronado is a large flying boat patrol bomber designed by Consolidated Aircraft, and used by the US Navy during World War II in bombing, antisubmarine, and transport roles. Obsolete by the end of the war, Coronados were quickly taken out of service. Only one known example remains, at the National Naval Aviation Museum at Naval Air Station Pensacola, Florida.

The Douglas XP3D was a prototype American patrol flying boat of the 1930s. A twin-engined high-winged monoplane, the P3D was produced by the Douglas Aircraft Company to equip the US Navy's Patrol squadrons, but despite meeting the Navy's requirements, the rival Consolidated PBY was preferred owing to a lower price.

The Hall XP2H-1 was an American prototype four-engined biplane flying boat of the 1930s. Intended as an experimental very-long-range maritime patrol aircraft, a single example was built. The XP2H-1 was the largest four engine biplane aircraft ever procured by the US Navy.

The Hall XPTBH was a prototype American twin-engined seaplane, submitted to the United States Navy by the Hall Aluminum Aircraft Corporation in response to a 1934 specification for new bomber and scout aircraft. Constructed in an innovative fashion that made extensive use of aluminum, the XPTBH proved successful in flight testing, but failed to win favor with the U.S. Navy. No production contract was awarded, and the single aircraft built served in experimental duties before its destruction in a hurricane during 1938.

The K-class blimp was a class of blimps built by the Goodyear Aircraft Company of Akron, Ohio for the United States Navy. These blimps were powered by two Pratt & Whitney Wasp nine-cylinder radial air-cooled engines, each mounted on twin-strut outriggers, one per side of the control car that hung under the envelope. Before and during World War II, 134 K-class blimps were built and configured for patrol and anti-submarine warfare operations, and were extensively used in the Navy’s anti-submarine efforts in the Atlantic and Pacific Ocean areas.

The Lockheed Hudson was an American-built light bomber and coastal reconnaissance aircraft built initially for the Royal Air Force shortly before the outbreak of the Second World War and primarily operated by the RAF thereafter. The Hudson was a military conversion of the Lockheed Model 14 Super Electra airliner, and was the first significant aircraft construction contract for the Lockheed Aircraft Corporation—the initial RAF order for 200 Hudsons far surpassed any previous order the company had received. The Hudson served throughout the war, mainly with Coastal Command but also in transport and training roles as well as delivering agents into occupied France. They were also used extensively with the Royal Canadian Air Force's anti-submarine squadrons and by the Royal Australian Air Force.

The Martin PBM Mariner was an American patrol bomber flying boat of World War II and the early Cold War era. It was designed to complement the Consolidated PBY Catalina and PB2Y Coronado in service. A total of 1,366 were built, with the first example flying on 18 February 1939 and the type entering service in September 1940.

The Northrop N-3PB Nomad was a single-engined American floatplane of the 1940s. Northrop developed the N-3PB as an export model based on the earlier Northrop A-17 design. A total of 24 were purchased by Norway, but were not delivered until after the Fall of Norway during the Second World War. Exiled Norwegian forces used them from 1941, operating from Iceland, for convoy escort, anti-submarine patrols, and training purposes from "Little Norway" in Canada. Within two years of delivery, the design was effectively obsolete in its combat role, and the remaining N-3PBs were replaced by larger aircraft in 1943.

The Sikorsky XP2S was an American biplane patrol flying boat developed for the United States Navy during the early 1930s.