Guide

Why anchors drag, and how to stop it

Most anchors that drag were never properly set, or had too little rode for the wind that came later. Here are the common causes, and what to do about each.

1. Too little scope. In a gust, a short rode pulls upwards on the anchor and breaks it out. Let out more, especially before wind that's forecast. Work it out with the scope calculator.
2. Not set. An anchor dropped and left alone often lies on the bottom without digging in. Let the boat fall back, then motor slowly astern and build up the power. Watch a transit on shore, or your GPS, to check that you've stopped moving.
3. Poor holding. Weed, rock, shingle and very soft mud hold badly. Sand and firm mud hold best. Check the chart's seabed notes, and look through the water or at the satellite view.
4. A wind shift or the tide turning. The anchor has to turn and reset. In weed or on a hard bottom it may not dig back in. Anchor for the forecast wind, not just the wind you have now.
5. Gusts and sailing at anchor. The boat yaws from side to side and jerks the rode. A snubber or bridle and more scope soften the loads.
6. A fouled anchor. A plastic bag, weed or your own chain around the anchor after a turn of the tide can stop it holding. If it dragged once, lift it and look before you drop it again.

If you drag

Start the engine and take the load off the anchor. Decide whether to re-anchor or move. At night, have a plan ready before you go to sleep.

Notice it early

Use a transit on shore, a GPS anchor alarm and a forecast you've checked. Anchor Mate sounds a loud alarm on every crew phone the moment the boat leaves its circle, and its wind alerts (Premium) warn you before a shift.

A guide, not a guarantee. Learn and practise anchoring with your own boat and gear.