[citation needed] The Canal opened a waterway from the Atlantic to the Pacific, bypassing the Strait of Magellan.

Due to U-boat operations, the Canal Zone was put under the Caribbean Defense Command in 1939.

Bases installed smoke generators, anti-aircraft guns, long-range radar systems, searchlights, and aircraft warning stations.

Troops were deployed to Colón, Margarita Island, and Toro Point's Fort Sherman.

Due to these defenses, U-boats and Imperial Japanese Navy submarines did not attack or approach the Canal Zone.

[3] With the loss of the Dutch East Indies oil fields, the vast Canal Zone tank farms became the supply line for fuel needed to fight the Pacific War.

To aid the war effort, fuel oil pipelines were built along the Canal, resulting in a decreased number of tankers traversing the waterway.

Japanese military trained for the Panama Canal attack, but the plan was canceled in June 1945 because the war was taking a toll on the country.

With Japan's surrender, the submarine aircraft carriers were insructed to destroy the planes, which were sunk.

[3][8] Base used to protect the Panama Canal Zone in World War II:[9] 9°18′37″N 79°53′03″W / 9.31035°N 79.88425°W / 9.31035; -79.88425 (Gatun Tank Farm) Canal Zone Naval Radio Stations Post World War II: Naval Station Coco Solo and Submarine Base Coco Solo was founded in 1917, near Fort Randolph, as a submarine base to protect the Canal Zone on the Atlantic Ocean side.

The Navy had a major ship and submarine repair base built at Coco Solo.

Submarine Base Coco Solo was also used as a training ground for new crews before being moved to more forward war action.

The base was very busy during World War II: with patrols, training, refueling and repairing vessels.

US Senator John McCain was born in 1936 at the small Navy hospital at Coco Solo Naval Air Station.

NAS Upham seaplanes did U-boat patrols over the Antilles, the Caribbean, and coasts of South America.

While the US did not enter World War II until 1941, On 8 September 1939, President Franklin D. Roosevelt issued a proclamation of a limited" national emergency.

After the bombing of Pearl Harbor the VP-32 at NAS Upham started patrolling the Pacific Ocean around the Panama Canal for Empire of Japan vessels also.

Later in the war the larger and newer Martin PBM Mariner seaplanes were added to NAS Upham.

Martin PBM had a bombing rack and in July 1943 three German U-boats were sunk after being found with the newer ASG radar.

After the crew was trained and the PT Boat completed sea trails, they would be sent to other US Naval Advance Bases.

The current Taboga Hotel was the PT-boat base barracks[26] 8°47′54″N 79°33′18″W / 8.7982°N 79.5549°W / 8.7982; -79.5549[27][28] Rodman Naval Station was founded in 1932 and construction was completed in 1937.

The east bank of the canal, Port of Balboa had become crowded, so the new base was built across the other side..

Before 1914, the Balboa was a marsh, before the US Navy took over the port, the site was developed by the Army Corps of Engineers during the Panama Canal construction.

[31] In 1915, a US Navy VLF transmission station opened that radioed commands to US submarines based at Port of Balboa.

The Navy also docked ships at Flamenco Island about 4 miles south of Port of Balboa.

[32] A 1921 rate card quotes a fee of 15 cents ($2.50 in 2022 dollars) per ton for dry docking and undocking, with a minimum charge.

[33] One of the first ship built at Balboa was the United States Navy patrol vesse, USS Pequeni in 1917.

Seabee both did construction and operated power plants, shore batteries, tank farm, did maintenance work and more.

Roosevelt checked on the progress of the Canal's construction and talked to workers about the importance of the project.