Forty-five fathoms is marked on the anchor chain by __________.

Correct Answer: Option C — three turns of wire on the third stud from each side of the detachable link

Standard chain marking protocols dictate that at 45 fathoms, the detachable link is identified by three turns of wire on the third stud from each side of the link. This system provides a tactile and visual reference for the bridge team to accurately determine the amount of chain deployed during anchoring operations.