
Installing An Anchor Windlass On Board
If you’re tired of hauling your anchor up by hand, installing a windlass is a game-changer. A windlass makes anchoring easier and safer, giving you more time to enjoy your time on the water.
In this guide, we’ll walk you through the installation process step by step, starting with choosing the right windlass for your boat.
Choosing the Right Windlass
Horizontal vs. Vertical Windlass
Windlasses come in two main types (see picture below):
- Horizontal Windlass – The gypsy (the cog that grips the chain) sits on the side, and the motor is housed above deck.
- Vertical Windlass – The gypsy is positioned on top, and the motor sits below deck.
Which One Should You Choose?
- Horizontal windlasses are easier to install and fully enclosed, making them a great DIY option.
- Vertical windlasses require more space below deck but provide a cleaner deck layout.
Top Tip: If your anchor locker is small, go for a horizontal windlass. If you have ample locker space, a vertical windlass is a good choice.

Types of Windlass
Windlass Power: What Size Do You Need?
Windlasses come in different power ratings, usually measured in watts. Some manufacturers list pulling power instead, so always check the specs. Use the guide below to determine the right size for your boat:
- Boats 18-25ft ---------- 300w
- Boats 23-30ft ---------- 500w
- Boats 28-38ft ---------- 700w
- Boats 36-43ft ---------- 1000w
- Boats 40-48ft ---------- 1500w
- Boats 46-60ft ---------- 2000w
If your boat is on the heavier side or has a high windage area, opt for a slightly more powerful windlass.
Planning Your Windlass Installation
When planning your installation, you will need to take in to account several things. We’ll go through them step by step to keep it reasonably logical.

Deck Strength, Location and Chain Drop.
The windlass will ideally need to be mounted over a reasonably deep area of the anchor locker, and the chain should drop pretty much straight down.
In our experience trying to route the chain down through pipes or at an angle is often risky. It’s well worth shopping around different windlasses type to make sure you can get the ‘drop’ in the right place.
This should idctate the ‘zone’ in to which you will be able to mount your windlass, now lets look at this area in more detail.
- Is the deck flat? If the deck isn’t flat, you may need to make a shim or plate. The windlass will be tightly fixed down. If the deck is bent, this could get damaged when the fastenings are tightened.
- Check the strength of the deck, is it reinforced? If you are unsure, you might need to add support. You can do this by fibreglassing in a backing sheet or adding a metal plate. This will help spread the load on the underside of the deck over a larger area.
- Is there a door to the anchor locker in the way?
Pay attention to the height difference between the bow roller (more on these later) and the windlass too. Anchor chain shouldn’t enter the gypsy of a vertical windlass at more than a few degrees off dead straight. Horizontal windlasses are a little more forgiving in this respect, but even so the chain angle shouldn’t be more than 10 degrees or so of the horizontal as the gypsy needs a good grip.
So remember:
- Mount the windlass over a deep part of the anchor locker for a straight chain drop.
- Avoid routing the chain through pipes or at angles—it can cause jams.
- Ensure the deck is strong enough to handle the windlass. Reinforce it with a backing plate if needed.
- Check the chain’s entry angle—vertical windlasses require a nearly straight drop, while horizontal ones allow up to 10 degrees of variation.

Power Supply Considerations
Getting power to the windlass is not quite as difficult as it once was, but still needs to be factored in. Modern windlasses are more efficient, meaning separate batteries are usually unnecessary for models under 700W. However, longer cable runs require larger cable sizes:
Windlass Power | 0-7m Cable Run | 7-15m Cable Run | 15-24m Cable Run |
300W | 10mm² | - | - |
500W | 10mm² | 16mm² | - |
700W | 16mm² | 25mm² | - |
1000W | 25mm² | 35mm² | - |
1500W+ | Battery at bow recommended |
Generally anything larger than 1000w will need a battery to be placed near the windlass in the bow of the boat, but smaller cables will still need to be run forward to charge this battery.

Windlass Controls
At this stage, how you control the windlass is less important. However, if you are running battery cables, it is a good idea to run smaller control cables at the same time.
Most windlasses are controlled by a solenoid switch or ‘contacter box’. This is normally supplied with the windlass. These solenoid switches control the current flowing in the windlass. They themselves are controlled by smaller switches that we press to activate the windlass.
- Foot switches – Mounted near the windlass for easy access.
- Toggle switches – Installed at the helm for remote control.
- Wired remotes – Plug in when needed.
For flexibility, consider installing multiple control options, especially if you sail solo. It’s no good having foot switches at the bow if you often use the boat single handed. Conversely a toggle switch at the helm can be frustrating when the person on the bow has better visibility of the situation.
Choosing the Right Chain
Windlasses are available with different sized ‘Gypsy’ units to fit different sizes of chain. It’s important to either buy a windlass that fits your chain. Otherwise be sure to budget for new chain if the chain you have is either wrong or not calibrated for use with a windlass.
Your windlass must match your chain size. Common chain sizes are:
Boat Size | Chain Size |
18-25ft | 6mm |
25-36ft | 8mm |
36-48ft | 10mm |
45-60ft | 12mm |
Check if your chain is DIN766 or ISO calibrated—these are the most common standards.

Anchor & Bow Roller Compatibility
Windlasses will work with most types of anchor, but it’s worth checking that your anchor is ‘self launching’. This means that when the anchor is in a horizontal bow roller, it will launch itself. This happens when the chain is loosened by letting out chain with the windlass. Non self launching anchors require a shove to get them over the front of the boat.
Things To Consider:
- Ensure your anchor is self-launching, meaning it releases when the chain slackens.
- Popular self-launching anchors: Delta, Rocna, Manson, and Spade.
- If using a Bruce or CQR anchor, you may need a tilted bow roller to assist launching.
- Your bow roller should be sturdy and well-secured to handle the anchor’s force.
Final Checks Before Installation
- Ensure proper chain drop alignment – A misaligned chain can cause jams.
- Check deck reinforcement – Add a backing plate if necessary.
- Verify power supply and cable size – Use the correct gauge wire to prevent voltage drop.
- Decide on control placement – Install foot and helm switches for convenience.
- Confirm anchor compatibility – Make sure your anchor self-launches.
By following these steps, you’ll ensure a smooth installation and enjoy effortless anchoring on your next voyage!