Why Are Anchor Chains Painted Different Colours? A Skipper Explains

Look closely at the anchor chain on almost any cruising yacht and you'll see blocks of colour every few metres: red, yellow, white, blue. Guests often think it's decoration. It isn't. Those marks answer the most important question when you anchor: how much chain is out right now?

Why the length of chain matters so much

An anchor holds best when it's pulled along the seabed, not upwards. Think of it like a garden fork: pull it flat and it digs in; pull it straight up and it comes out.

The chain does that job. Its weight makes it sag in a curve between the boat and the anchor. The more chain you put out, the more of it lies flat on the bottom, and the lower the angle of pull on the anchor. In a gust, the boat first has to lift that heavy chain before it can pull the anchor at all. That works like a shock absorber.

Too little chain, and the angle gets steep. The anchor gets pulled up instead of along, and it drags.

What the colours mean

The marks tell the crew how many metres have gone over the bow roller. Typically there's a mark every 10 metres, with a different colour or number of bands for each.

There's no single worldwide standard. Every boat has its own system, so the first thing I do on a new boat is check how the chain is marked.

One smart trick: change the colour pattern at bigger intervals, for example every 50 metres. If a mark wears off or you lose count, the colour change still tells you roughly where you are.

Many boats also paint the last few metres of chain bright red. When you see red, you're almost at the end, and it's time to stop.

Why not just use the chain counter?

Most modern yachts have an electronic chain counter at the helm or on the windlass remote. It's useful. But it can be wrong: it needs resetting, the sensor can fail, and it needs power.

Paint needs none of that. At night, in a squall, or when the electronics are off, a quick look at the colours gives you the answer. That's why many experienced sailors still trust the marks more than the counter. Paint doesn't run out of batteries.

How much chain should you put out?

The ratio of chain to depth is called scope. A common guideline:

Conditions	All-chain	Chain and rope
Normal	5:1	7:1
Strong wind or overnight	7:1	10:1

The important part is what you measure. It's not just the depth on the sounder:

Chain needed = scope × (water depth + bow height above the water + tide rise)

Example in Croatia: you anchor in 8 metres. The bow roller is about 1.5 metres above the water, and the tide in the Adriatic is small, so add about 0.5 metres. That's 10 metres in total. At 5:1, you need about 50 metres of chain. If a bora is forecast, go to 7:1, about 70 metres, if you have the swinging room.

On a crowded summer anchorage, the limit is often the space around you, not the chain. More chain means a bigger swinging circle, so look at your neighbours before you drop.

How to mark your own chain

1. Flake the chain out on a dock or in a clean, dry place.
2. Measure from the anchor shackle, not from the bitter end.
3. Choose a pattern and write it down. Stick the key near the windlass.
4. Mark it. Paint is cheap and very visible but wears off each season. Plastic chain markers that clip into the links last longer and come in colours. Cable ties are easy to replace but can snag in the windlass.
5. Check the marks every season and refresh any that have faded.

Need markers in a specific size or colour for your chain? AXLY can print custom parts in flexible, UV-resistant marine materials, from a single piece.

Anchoring a catamaran

On a cat, the chain usually comes down between the hulls and is held by a bridle: two lines from each bow to a hook on the chain. The bridle takes the load off the windlass and stops the boat swinging so much. The chain marks matter just as much, because you're still counting metres before you set the bridle.

Captain's note

Anchoring is where many charters go wrong, and most of the time it's because nobody knew how much chain was out. A few colours on the chain fix that problem for almost nothing.

See you on the water,
Captain Phil