[1] He passed studentexamen in Djursholm in 1938[1] and began his naval career as a teenager and schoolboy by internship aboard destroyers and cabin boy brigs.

Two years later, he served on the destroyer HSwMS Klas Horn (3) and was recommended for entry into the Royal Swedish Naval Academy.

[2] At the outbreak of World War II in 1939, Lindgren, who belonged to the junior course, was sent home, while the older course were directly appointed acting sub-lieutenants").

On 25 November 1943, Lindgren served aboard the destroyer HSwMS Norrköping (J10) when it, among the breaking waves at Bogskär south of Åland, in full storm salvaged a life raft belonging to the German steamer Casablanca.

[2] Lindgren was captain of the destroyer HSwMS Småland (J19) from 1959 to 1961 and he attended the Swedish National Defence College in 1961.

[1] From 1962 to 1966, Lindgren was a teacher at the Swedish National Defence College, after which the sea service was terminated in 1966-67 with the commanding of Älvsnabben during its round-the-world trip with the then Crown Prince Carl Gustaf as officer candidate on board.