Yup, that'd be Lieutenant (2nd Class) by US terms. Only the US Navy does it differently, calling the Lieutenant (2nd Class) by the unusual term Ensign, which gives us the confusion at hand.
Timo Saloniemi
I have never heard of a lieutenant (2nd class) in the US navy.
Comparing ranks between different countries is confusing.
As far as I can tell, naval cadets in the US Naval academy are called midshipmen, which may or may not agree with the words for naval cadets in other countries and languages.
The lowest commissioned officer rank in the US navy is ensign, which is the equivalent of 2nd lieutenant in the army; both are pay grade O-1.
Next is lieutenant junior grade, equivalent to a first lieutenant in the army. O-2.
Next higher is lieutenant, equivalent to a captain in the army. O-3.
Next higher is lieutenant commander, equivalent to a major in the army. O-4.
Next higher is commander, equivalent to a lieutenant colonel in the army. O-5.
Next higher is captain, equivalent to a colonel in the army. O-6.
Next higher is commodore, or in the present era rear admiral lower half, equivalent to a brigadier general in the army. O-7.
Next higher is rear admiral, equivalent to a major general in the army. O-8.
Next higher is vice admiral, equivalent to a lieutenant general in the army. O-9.
Next higher is admiral, equivalent to a general in the army. O-10.
Fleet Admiral and Admiral of the Navy are higher ranks that would never be used except in a big war.
Ensign and lieutenant junior grade are both listed as OFF-1 in the NATO system, so admiral is O-10 in the US system and OFF-9 in the NATO system.
https://en.wikipedia.org/wiki/United_States_Navy_officer_rank_insignia
As near as I can tell, Finland has eleven ranks from their equivalent of ensign to admiral, with an extra rank of kapteeniluutnantii or captain lieutenant between senior lieutenant and lieutenant commander.
https://en.wikipedia.org/wiki/Finnish_military_ranks#Navy_operational_ranks