USCG Exam PracticeAnchoring and mooring operations
A vessel is riding to a single anchor when the officer of the watch notices the chain alternately going slack and then jerking taut with vibration felt through the chain. The vessel's GPS anchor-watch alarm has not yet triggered. What is the most likely explanation for this behavior, and what immediate action is indicated?
- A. The chain is surging due to wave action; no action is required until the GPS alarm activates
- ✓ The anchor is dragging; veer additional scope or let go a second anchorCorrect
- C. The chain stopper has parted; heave in on the windlass immediately to prevent loss of the anchor
- D. The swivel has seized, causing the chain to twist; slack the brake and allow the chain to run free
Why B is correct
NAVEDTRA 14343 §4-2 specifically identifies a chain that goes slack then jerks taut ('grumbling' or vibration) as a warning of dragging. The prescribed responses are to veer more scope or let go a second anchor. Waiting solely for a GPS alarm is not consistent with the requirement under 33 CFR §164.19(b) to follow procedures to detect dragging.