A well-rigged anchor gives you peace of mind, whether you're stopping for lunch, fishing a reef or staying overnight. A poorly rigged one can drag, part or jam at exactly the wrong moment. This guide covers the basics of setting up an anchor rode: chain, rope, shackles, swivels and marking. Most of it you can do yourself.
The parts of an anchor system
- Anchor: sized for your boat's length, displacement and the seabed you use most (sand, mud, weed or reef).
- Chain: adds weight, keeps the pull on the anchor horizontal and resists abrasion on the seabed.
- Rope (warp): provides length and stretch to absorb shock loads.
- Connectors: shackles, swivels and thimbles join everything together.
- Bow fittings: bow roller, cleat or windlass and a secure bitter end inside the anchor locker.
How much chain and rope?
A common rule for recreational boats is a length of chain at least equal to the boat's length. Some owners use a minimum of 6–10 metres on small boats, and all-chain rodes on larger cruising vessels. Total rode length depends on the depth you anchor in. A scope of at least 5:1 (rode out to depth) is a good starting point in moderate conditions, increasing to 7:1 or more in strong wind. Remember to include the height of your bow above the water in the depth figure. Check your state's marine safety regulations for any minimum anchor and rode requirements for your boat size and operating area.
Joining rope to chain
There are two common methods:
- Rope-to-chain splice: the rope is spliced directly into the last chain link. It runs smoothly through a windlass gypsy and is the preferred method for windlass setups.
- Eye splice with thimble and shackle: the rope is spliced around a stainless thimble, then shackled to the chain. It's strong and easy to inspect, but won't pass through most windlasses. A stainless steel thimble protects the rope eye from chafe.
Shackles: getting them right
The shackle is often the weakest link. Follow these rules:
- Choose a shackle with a working load at least equal to your chain. As a general rule, the shackle pin should be one size larger than the chain.
- Use quality stainless or galvanised shackles. Avoid mixing metals where you can, to limit corrosion.
- Always mouse (seize) the shackle pin with stainless or monel wire, or use a cable tie as a temporary measure, so it can't unscrew.
- Inspect shackles every season and replace any that are worn, bent or corroded.
For light-duty connections such as tender anchors, small fittings or securing a float line, hardware like the 5mm D shackle or a pressed D shackle with screw pin is handy to have aboard. For the main anchor connection, match the shackle rating to the chain size.
Do you need a swivel?
An anchor swivel stops the chain twisting as the boat swings and helps the anchor come up the right way on the bow roller. If you fit one, choose a high-quality, rated swivel and attach it to the anchor via a shackle rather than directly, so side loads don't bend it. Some sailors prefer no swivel at all and rely on a well-mounted roller. Either approach works if it's done carefully.
Mark your chain
Knowing how much rode you've let out is essential for setting the correct scope. Coloured chain markers make it easy, even at night:
Mark every 5 or 10 metres and keep a note of the colour code at the helm.
Secure the bitter end
Tie the end of your rode to a strong point inside the anchor locker with a length of rope that can be cut in an emergency. Never shackle chain directly to the boat in a way you can't release quickly.
Setting the anchor
- Approach into the wind or current and stop the boat.
- Lower the anchor to the bottom. Don't throw it.
- Drift or reverse slowly while paying out rode to the chosen scope.
- Snub the rode on a cleat and apply gentle reverse to dig the anchor in.
- Take transits or use your GPS anchor alarm to confirm you're not dragging.
Seasonal inspection checklist
- Chain: check for rust, worn links and the galvanising condition.
- Rope: look for chafe, stiffness or UV damage near the splice.
- Shackles and swivels: check for wear, cracking and that mousing is intact.
- Bow roller and windlass: check rollers spin freely and fasteners are tight.
Rig it right
Big Burjos Marine stocks shackles, thimbles, chain markers and rigging hardware, shipped Australia-wide from Coomera, QLD. If you have questions about matching hardware to your chain size, get in touch with your boat details.