The classifications of navy ships don’t require much explanation. Battleships are vessels designed specifically for battle. Aircraft carriers transport airplanes across the ocean. Destroyers, like battleships, were intended specifically for combat. So it shouldn’t be difficult to guess what purpose seaplane tenders were built for.
As early as the First World War, these vessels were constructed to support seaplanes, which were aircraft that could take off and land on water. Seaplane tenders were also referred to as seaplane carriers if they were large enough to not only transport the craft but also house repair facilities. They predated aircraft carriers and were at first equipped with minimal armament. Even after aircraft carriers came into use, seaplane tenders continued to serve, as was the case with ships like the USS Curtiss (AV-4), which was present at the time of the Japanese attack on Pearl Harbor in December of 1941.
Though the word “tender” has various meanings, in naval parlance it’s used to describe a vessel designed to support other vessels. The history of the seaplane carrier dates back to 1911, three years before the outbreak of World War I. The French Navy used Foudre to carry seaplanes—a type of aircraft that came about in 1910—under the ship’s main deck and used a crane to lower them onto the surface of the sea. Unlike aircraft carriers, Foudre wasn’t initially designed to be able to launch her own craft, but in November 1913 she underwent modifications that included a 32’ 10” flat deck runway.
That same year, the Royal Navy commissioned HMS Hermes into service with a flying-off deck already in place. Foudre and Hermes may have come earlier, but HMS Ark Royal was the very first ship that was designed from the start to be a carrier. Foudre was originally designed and commissioned as a torpedo boat tender while Hermes was built as a Highflyer-class cruiser.
For the United States, the first seaplane tender could be said to have been the USS Mississippi, though she was actually built as a battleship. Other American seaplane tenders included the USS Langley (CV-1/AV-3), which became the first aircraft carrier in 1920 after being converted from a coal carrier. Along with the USS Curtiss, other seaplane tenders present at Pearl Harbor at the time of the attack included the USS Tangier (AV-8) and USS Avocet (AVP-4). The USS Wright (AV-1) was also stationed at Pearl Harbor but had departed on November 20, 1941 to Wake Island.
The United States built several seaplane tenders immediately before and during World War II, many of which patrolled in the Pacific. Japan also constructed several seaplane tenders as a means of supplementing the much more powerful aircraft carrier fleets. After World War II, the seaplane still had a role to play, but seaplane tenders were largely obsolete. Most were scrapped by the 1950s, while others were converted to helicopter repair ships.