[1] In 1927–1928, he studied at the Naval War School in Paris, where the French President also decorated him with the Legion of Honour, Knight rank.

He climbed through the ranks as the war progressed, in January 1942 becoming the commander of the Romanian Destroyer Squadron, the most powerful naval formation of the Romanian Navy and of the Axis Powers in the Black Sea, consisting of two destroyers (Regele-Ferdinand-class) and two scout cruisers Aquila-class).

In early 1943, he became the commander of the Romanian Black Sea Fleet, gaining the rank of Rear-Admiral in March that year.

They were of the British Power type, but licence-built in Romania at the Galați shipyard, being commissioned as Vântul, Vârtejul, Vulcanul, Vedenia, Viforul, and Vijelia.

The scale and importance of the operation can be attested by the usage in combat of all four Romanian destroyers, the largest Axis warships in the Black Sea.

The last phase of the evacuation (10–14 May) saw the fiercest combat, as Axis ships transported, under constant attacks from Soviet aircraft and shore artillery, over 30,000 troops.

During the night of 27 April, a convoy escorted by the Romanian gunboat Ghiculescu, the German submarine hunter UJ-115, one R-boat, two KFK naval trawlers and 19 MFPs (including the Romanian PTA-404 and PTA-406) engaged the Soviet G-5-class motor torpedo boats TKA-332, TKA-343 and TKA-344, after the three attacked and damaged the German submarine hunter UJ-104.

Macellariu's successful conduct of the evacuation and the achievements obtained by the Romanian warships under his command, in combat and number of Axis troops evacuated, earned him the Knight's Cross of the Iron Cross (Crucea de Cavaler a Crucii de Fier, in Romanian).

However, after a face-to-face meeting with Macellariu, he was persuaded to make an orderly retreat and avoid an unnecessary and costly battle.