During his reign, Peter I the Great led a cultural revolution based on the Enlightenment with a lasting impact on Russia. Regarding Russian Navy, he ceaselessly sought appropriate ensigns until approving in 1700 a flags set inspired on those of the English (later British) Navy - with a white, a blue and a red ensign for each of the Fleet's sections. The white ensign still suffered a further change in 1712, when it adopted the current form.
Source: Flags of The World (FOTW) website:Russian Navy: fleet sections (I)
Sizes: ensign W12 x L18 mm, mast flags W8 x L12 mm, jack W6 x L9 mm, pennant W4 x L48 mm.