On September 16, 1870, Baer was accepted as a student into the Naval Cadet Corps and graduated on March 31, 1871 as a Garde de la Marine.

He arrived at Shanghai on August 1, 1876, to retrieve the gunboat Sable three days later, before being given command of the 3rd Company of Siberian Naval Crew from December 20, 1877 to January 11, 1878.

By July 4, 1879, he was transferred to the clipper Abrek as the auditor before being promoted to Lieutenant on January 1, 1880, but was decommissioned on October 21 due to poor health from being in Siberia.

On July 2, 1901 he was made chairman of the artillery at the Geisler and Co. electrical plant installed on the Varyag but surrendered command on March 1, 1903.

By July 14, 1903, he requested a two-month leave due to illness and from December 6, 1903, to January 26, 1904, he was given command of the 17th Naval Crew.