How to Anchor a Boat

Anchoring well is a handful of simple things done in the right order. Get the spot, the scope and the set right, keep a watch, and you can leave the boat and sleep. Here is the whole process, start to finish.

1. Choosing an anchorage

A good anchorage gives you three things: shelter from wind and swell, good holding, and enough room. Look for protection from the direction the weather is coming from — and from where it is forecast to go, since wind shifts catch out sailors who anchored for the conditions on arrival. Check the chart and pilot for the bottom type and for hazards, and eye up how busy it is before you commit.

2. Reading the bottom

Holding depends on what is under you. Sand and firm mud generally hold well; weed, soft mud, shingle and rock are less reliable. Charts mark the bottom type with abbreviations, and your depth sounder and the behaviour of the anchor will tell you the rest. If the anchor will not bite after a couple of honest attempts, move — hope is not a holding ground.

3. How much scope

Scope — the ratio of rode to depth — is the single biggest factor in holding. As a starting point, let out about five times the depth on all-chain rode and seven times on rope, measured from the bow roller and allowing for the rise of tide, then more as the wind builds. This matters enough to have its own guide: read anchor scope explained for the full method and a table by depth.

4. Setting the anchor, step by step

1. Choose your spot

   Pick your position with shelter, good holding and room to swing, and note the depth and the boats around you.

2. Prepare and approach

   Ready the anchor and flake the rode so it runs freely. Motor slowly up to your spot, ideally heading into the wind or tide so the boat is under control.

3. Lower the anchor

   Stop the boat over your chosen point and lower the anchor to the seabed under control — do not throw it, which piles chain on top of it.

4. Fall back and pay out scope

   Let the boat drift back with the wind or tide, paying out rode steadily until you have the scope you want. Feeding it out as you go lays the chain along the bottom rather than in a heap.

5. Set the anchor

   Snub the rode on a cleat and gently increase astern power. A set anchor brings the boat up firmly and holds; a dragging one keeps sliding. Feel for it and watch a transit ashore.

6. Check and keep watch

   Take a transit or note your position, look at your swing relative to others, and set an anchor alarm before you relax.

5. Swing room

Once set, your boat will swing in an arc as the wind and tide change. You need enough clear water around you for that whole circle, and you need to allow for the fact that boats on different rodes and of different types swing differently. Our guide to the anchor swing circle explains how to judge it, especially in a crowded anchorage where getting it wrong means a midnight collision.

6. Keeping an anchor watch

The last step is the one that lets you actually rest: a watch. In settled conditions a well-set-up anchor alarm is a better watch than a tired human, monitoring your position continuously and waking you the moment the boat leaves its circle. In heavier weather, keep a human watch alongside it. Either way, set the alarm before you settle — the difference between watch and alarm is covered in anchor watch vs anchor alarm.