The list of ship launches in 1981 includes a chronological list of all ships launched in 1981.
HMS Invincible was the Royal Navy's lead ship of her class of three light aircraft carriers. She was launched on 3 May 1977 as the seventh ship to carry the name. She was originally designated as an anti-submarine warfare carrier, but was used as an aircraft carrier during the Falklands War, when she was deployed with HMS Hermes. She took over as flagship of the British fleet when Hermes was sold to India. Invincible was also deployed in the Yugoslav Wars and the Iraq War. In 2005, she was decommissioned, and was eventually sold for scrap in February 2011.
HMS Hecla was the lead ship of the Hecla class, an oceangoing survey ship type in the Royal Navy. She was ordered in the mid-1960s, along with her sister ships HMS Hecate and HMS Hydra. A fourth ship, HMS Herald, was completed in the early 1970s. The ship served for thirty years in this role, and various others, before finally being replaced by HMS Scott in 1997. Hecla was sold to private interests, being renamed "Bligh" after Vice-Admiral William Bligh. After this, the vessel was used in a hydrographic survey of Irish waters, and was based in Waterford, Ireland.
HMS Hecate (A137) was a Royal Navy deep ocean survey vessel of the Hecla class. She was present at the "presentation of fleet colours" review in Torbay on 29 July 1969. The ship was decommissioned in 1990.
HMS Herald was a Hecla-class ocean survey ship that served with the Royal Navy during both the Falklands War and Gulf War.
USS Samuel N. Moore (DD-747), an Allen M. Sumner-class destroyer, is the only ship of the United States Navy to be named for Samuel N. Moore.
The Nanuchka class, Soviet designation Project 1234 Ovod, are series of corvettes built for the Soviet Navy and export customers between 1969 and 1991.
HNLMS Van Speijk (F802) was a frigate of the Van Speijk class. The ship was in service with the Royal Netherlands Navy from 1967 to 1986. The ship's radio call sign was "PAVA". She was sold to the Indonesian Navy where the ship was renamed KRI Slamet Riyadi (352). The ship was decommissioned in 2019.
KRI Oswald Siahaan (354) is an Ahmad Yani-class frigate operated by the Indonesian Navy. Prior to her service in the Indonesian Navy, she served in the Royal Netherlands Navy as Van Speijk-class frigateHNLMS Van Nes (F805).
HNLMS Evertsen (F815) was a frigate of the Van Speijk class. The ship was in service with the Royal Netherlands Navy from 1967 to 1989. The ship's radio call sign was "PAVG". She was sold to the Indonesian Navy where the ship was renamed KRI Abdul Halim Perdanakusuma (355).
HNLMS Isaac Sweers (F814) is a frigate of the Van Speijk class. The ship was in service with the Royal Netherlands Navy from 1968 to 1990. The ship's radio call sign was "PAVF". She was sold to the Indonesian Navy where the ship was renamed KRI Karel Satsuitubun (356).
HNLMS Tjerk Hiddes (F804) was a frigate of the Van Speijk class. The ship was in service with the Royal Netherlands Navy from 1967 to 1986. The ship's radio call sign was "PAVC". She was sold to the Indonesian Navy where the ship was renamed KRI Ahmad Yani (351).
ARA Bahía Paraíso was an Argentine Navy auxiliary ship that sank in 1989, 2 miles (3.2 km) from Palmer Station at Arthur Harbor, Antarctica, resulting in a 170,000 US gal oil spill.