It appears to be the early 18th century. Peter the Great was the first Russian monarch to have a strong interest in naval affairs. According to Wikipedia,

"A strategy to 'explore the Far East via India and the Philippines to establish trade links.' was suggested to Peter the Great by the Siberia Governor Fydor I. Semyonov in 1722."

The Russians first reached Okhotsk in 1647 by land, and built a base there. But it was in 1714 that Peter the Great sent shipbuilders to the Pacific to build ships and explore the Pacific Ocean. This effort resulted in, or perhaps was inspired by growing Russian knowledge of the Paciic.

It appears to be the early 18th century. Peter the Great was the first Russian monarch to have a strong interest in naval affairs. According to Wikipedia,

"A strategy to 'explore the Far East via India and the Philippines to establish trade links.' was suggested to Peter the Great by the Siberia Governor Fydor I. Semyonov in 1722."

The Russians first reached Okhotsk in 1647 by land, and built a base there. But it was in 1714 that Peter the Great sent shipbuilders to the Pacific to build ships and explore the Pacific Ocean in order to support the fur trade from Kamchatka. This effort resulted in, or perhaps was inspired by, growing Russian knowledge of the Pacific.