Staying put

~9 minAnchoring & mooring

An anchor does not hold by weight — it holds by digging in, and it can only dig if the pull along the seabed is horizontal. That is what scope is for: with chain, a working minimum of four times the maximum depth of water (more in wind, more with rope). Short scope lifts the shank and turns a good anchor into an expensive plough.

Choosing the spot is tide-and-chart work you already know: enough depth at low water for your draught, enough scope at high water for your chain, holding ground that bites — sand and mud are good, weed and rock are lottery tickets — shelter from the forecast wind (and the forecast shift), room to swing clear of neighbours, and no cables, moorings or fairways underneath. The struck-through anchor symbol on the chart settles the last point.

Laying it: bring the bow head to wind or tide, stop, lower — never hurl — the anchor to the bottom, then fall back as you pay out scope, and dig it in with a burst of astern. Proof of holding: pick a transit abeam — two fixed objects in line — and watch it; if the transit holds while the boat settles, you are anchored. Then set an anchor alarm or note swinging-circle bearings, because the test continues all night.

A tripping line — a light line from the anchor’s crown to a small buoy — is cheap insurance on foul ground: it pulls the anchor out backwards when the usual way is stuck.

Set the scope yourself — then slide the tide up and watch a safe 4:1 quietly become a dragging 2.5:1.

Choosing and weighing

Anchors come in families, and each has a temperament. The plough types (CQR-style, and the modern spade/scoop generation that mostly out-performs them) are the everyday bower — the main anchor on the bow — happiest in sand and mud. The danforth’s flat flukes fold for stowage and bite hard in soft bottoms, which makes it the classic kedge — the lighter second anchor you row out or deploy from the stern. The claw sets easily but holds modestly; the old fisherman pattern is poor everywhere except the kelp and rock where nothing else works. Whatever the pattern, the honest rule: carry one good bower a size heavier than the chart suggests, and know where the kedge is stowed.

Weighing anchor reverses the laying: motor slowly up towards the anchor as the crew brings in the slack — never drag the boat to the chain with the windlass, it is not built for that — and when the chain is straight up and down, the anchor usually breaks out as the bow rises. Stubborn? Snub the chain at short stay and let the boat’s own pitching work it loose. Properly fouled, the tripping line you laid earns its keep — or motor gently in a circle to back the flukes out the way they went in.

Check yourself

A common minimum scope when anchoring with chain is…

Good holding ground for most anchors is…

Choosing an anchorage, you should check…

How do you confirm the anchor is holding after letting go?

Picking up a mooring buoy under power is best done…

Answers count towards your topic mastery on the exercises page.