How do I install an electric anchor windlass on my boat?

Fit an electric anchor windlass by matching its gypsy to your chain, mounting it on a properly reinforced deck and installing a dedicated, protected battery supply. Check the chain lead and locker depth first: even a powerful windlass will jam if the chain cannot enter straight and fall freely below it.

1. Check chain and locker dimensions

Measure the chain diameter and identify its calibration before ordering. An 8 mm gypsy does not accept every 8 mm chain. DIN 766 and ISO 4565 dimensions can differ, particularly at certain larger sizes. Ask the supplier to confirm compatibility using a chain sample or its documented specification.

Choose the windlass using the maker's boat-size and anchoring-load guidance, allowing for displacement, anchor weight and chain weight. A common starting point is a maximum pull of at least three times the combined weight of the anchor and entire chain. Check working load and duty cycle too.

• Vertical windlass: compact above deck, with its motor below; needs space beneath the mounting and sufficient chain fall.
• Horizontal windlass: motor above deck, often easier to fit where locker space is restricted, but still needs the specified chain fall.

Follow the installation drawing for clearance between the chain outlet and the top of the accumulated chain pile. Around 300 to 450 mm is common, but requirements vary. Check access for the motor, gearbox, terminals and manual recovery handle.

2. Reinforce and seal the mounting

Position the supplied template so the chain runs correctly from the bow roller onto the gypsy. Check the specified entry angle, clearance from the locker lid and the route through the chain opening. Inspect beneath every proposed hole before drilling.

1. Expose the underside and check for wet core, thin laminate, wiring and obstructions.
2. Fit a substantial backing plate or structural reinforcement to spread loads into sound deck structure. A few large washers are insufficient on a lightly built deck.
3. On a cored deck, remove core locally around penetrations, replace it with thickened epoxy, then redrill after curing. Use solid compression support beneath loaded fasteners.
4. Bed the base and fasteners with a compatible marine sealant, keeping drains clear. Tighten to the windlass manufacturer's torque specification; there is no universal mounting torque.

Fit a suitably reinforced chain stopper or strong securing point so anchoring loads bypass the windlass. Provide a snubber attachment and an independent anchor restraint for passage.

3. Size and protect the supply

Isolate the battery supply before working. Keep hands, clothing and tools clear of the gypsy whenever power is connected.