You are approaching a crowded anchorage at dusk. The owner wants to anchor for the night. You have a suitable berth in mind, the depth is 12 metres, the bottom is sand over clay. Now the preparation, execution and watchkeeping decisions must be precise — the examiner will pull any one of these threads.
Pre-Anchor Assessment
Before committing to the approach, confirm:
- Suitability of the bottom (chart symbol, nature of seabed)
- Swinging room — account for your own vessel's scope and the swinging circles of neighbours; vessels may be lying to different influences (wind vs. tide)
- Depth across the entire swinging circle at the lowest predicted tide
- Any underwater cables, pipelines, or restricted areas on the chart
- Whether anchoring is permitted (port authority NOTAMs, local regulations)
- Wind and tidal forecast for the duration of the stay
Preparing the Ground Tackle
- Walk the anchor to the waterline ("at the waterline" or "on the brake") before the approach — do not anchor with the anchor still in the hawsepipe
- Count and mark cable: standard markings every shackle (27.5 m); know your vessel's marking system
- Brief the foredeck team: method of communication (hand signals preferred in noise/wind), signals for let go, holding, dragging
- Establish a clear abort plan with the bridge
Letting Go
- Approach the chosen position slowly, heading into the dominant element (wind or tidal stream — whichever is stronger)
- When the vessel has slight sternway or is stopped over the ground, let go — this ensures cable runs forward away from the anchor and does not pile on top
- Veer cable in a controlled manner; never let it run free from depth
- A commonly used rule of thumb: in moderate conditions, veer 3–5 times the depth in cable (scope). In deteriorating conditions or an exposed anchorage, increase scope accordingly
Confirming the Anchor is Holding
- Take two or more (preferably three) bearings or a GPS position immediately after the cable is taut
- Apply a short burst astern to set the anchor; watch transits or check COG/SOG on ECDIS/chart plotter
- Mark the position on the chart/ECDIS; plot the swinging circle
- The vessel should lie quietly to the cable; cable should lead forward and down, not out horizontally (which can indicate dragging or sailing at anchor)
Anchor Watch
- Maintain a continuous watch; set anchor alarm on GPS/ECDIS with an appropriate radius
- Monitor the cable lead, weather trends, and neighbouring vessels
- Check depth regularly — a drop in depth or change in cable lead can indicate dragging
- Log: time of anchoring, position, depth, cable veered, bottom quality, bearings of fixed objects
In Poor Holding Ground or Deteriorating Conditions
- Veer more cable
- Consider a second anchor (open hawse or backing anchor)
- Maintain readiness to weigh anchor or motor to relieve cable load