Ship-of-the-line lieutenant is a common naval rank, equivalent to the modern naval rank of lieutenant in the UK, Commonwealth and US. The name of the rank derives from the name of the largest class of warship, the ship of the line, as opposed to smaller types of warship (corvettes and frigates).
While obsolete in most modern navies, some naval forces and merchant fleets still use the rank: lieutenant de vaisseau in French, tenente di vascello in Italian, teniente de navío in Spanish, sorhajóhadnagy in the Hungarian, and Linienschiffsleutnant in the Austrian merchant fleet, while the German Bundesmarine and German merchant fleet use the rank of Captain lieutenant (Kapitänleutnant), like it is the case in other European navies.
The NATO rank code is OF-2.
Insignia in the French Navy
Insignia in the Italian Navy
Teniente de navío (ship-of-the-line lieutenant) of the Armada Española (Spanish Navy)
Insignia of a Linienschiffsleutnant in the Austro-Hungarian Navy