HMHS Britannic filming the wreck for National Geographic. In 2012, on an expedition organised by Alexander Sotiriou and Paul Lijnen, divers using rebreathers successfully installed and recovered scientific equipment used for environmental purposes, to determine how fast bacteria are eating "Britannic"s iron compared to "Titanic". Having her career cut short in wartime, having never entered commercial service, and having had few victims, "Britannic" did not experience the enthusiasm aroused upon the mention of her name, unlike that of her sister ship "Titanic". After having been long ignored by the public, she finally gained fame when her wreck was discovered. Her name was
Sister ship an . The most famous sister ships were the White Star Line's , and . As with some other liners, the sisters worked as running mates. Other sister ships include the Royal Caribbean International's and . "Half-sister" refers to a ship of the same class but with some significant differences. One example of half-sisters are the First World War-era British s where the first two ships had four guns, but the last ship, , had two guns instead. Another example is the American s of the Second World War that came in "long-hull" and "short-hull" versions. Notable airships include the