While still a student at the Academy in 1725, he took part in the first long-distance foreign voyage of the young Russian fleet.
The young sailor soon attracted the attention of his superiors and was appointed to the post of adjutant to the chief commander of the Kronstadt port, which at that time was Admiral Thomas Gordon.
Two years later, due to his having experience and excellent knowledge in navigational and hydrographic matters, Ovtsyn was appointed to the great Northern expedition, led by Vitus Bering.
In 1734–1738, Ovtsyn led one of the units of the Second Kamchatka expedition that charted the coastline of the Kara Sea east of the river Ob.
A cape on the Taimyr Peninsula and a strait between the islands Oleniy and Sibiryakov bear his name.