Convert from sadzhen to fathom [ancient]

Unit Definition (sadzhen)
The sadzhen is a traditional Russian unit of distance corresponding roughly to the English fathom and French toise. Early in the 1700s, Czar Peter the Great fixed the length of the sadzhen at exactly 7 English feet. This equals 3 arshin or 2.1336 meters. Sagene is an older transliteration of the Russian word.

Unit Definition (fathom [ancient])
A fathom is a unit of measure equal to 2 yards or 6 feet, or 1.8288 metres. The name of the unit derives from the Old English word fæthm meaning 'outstretched arms' which was the original definition of the unit's measure.