BOTH INTERNATIONAL & INLAND What shape will a vessel 30 meters in length aground display?

Correct Answer: Option D — three black balls in a vertical line

Rule 30(d) of the COLREGS and Inland Rules mandates that a vessel aground shall exhibit three black balls in a vertical line during daylight hours. This visual signal alerts other mariners that the vessel is restricted in its ability to maneuver due to being fast to the bottom.