Professional skipper Simon Philips shares his method for mast climbing safely and confidently with only one other crewmember aboard

Mast climbing is a skill some sailors love to put into practice, while others, even seasoned professional yachtsmen, loathe the dizzying heights involved in even the simplest of mast-top maintenance tasks, writes Simon Philips.

Modern yachts, often with precious little in the way of steps to climb, in most cases rely on a safe system of lines to get up and down the mast, which can be pretty daunting.

No matter whether you are mast climbing to change a bulb in the tricolour on a windless day alongside in a marina, or freeing up a jammed line that’s much more critical out at sea, having a routine that’s well practiced is at the heart of making mast climbing safe and stress free.

crew on a yacht watching someone mast climbing

Large crews can easily hoist someone aloft, but it is still possible for small crews

Practice and preparation is key.

Getting familiar with the techniques and equipment will mean you’re better equipped 
to go aloft should the need arise at sea, which will inevitably be when you least expect it.

When I train round-the-world yacht race
 crews on their 70ft yachts, ideally there are
 seven people involved, just to hoist one 
up the mast.

I have two separate halyards involved and I have two people on a grinder, 
two people tailing (one per winch), two people
 on the clutches and one person watching the person going aloft who tells everyone what 
to do.

This way, there is a great safety margin involved.

But even when shorthanded, it’s still possible to go climb the mast safely.

1 Prepare to mast climb

A skipper checking halyards on a crew member before he goes aloft

Ensure the person going aloft has all they need with them

Prepare the person going aloft.

They should have shoes rather than bare feet, a comfortable bosun’s chair
 or climbing harness, and a helmet (cycling, skiing or kayaking) to help prevent head injuries.

Take a smartphone, so a photo
 can be sent to someone on the deck if necessary, saving a second hoist, and 
put your basic tools in the pocket of the bosun’s chair.

Ideally, all loose items should be attached by lanyards so that they can’t be dropped on to the deck

2 Halyards

mast climbing preparation

Using two halyards is a must to ensure the safety of the person aloft.

Decide which is the primary halyard and which is the safety halyard.

Use only halyards that are internal to the mast, like a headsail or mainsail halyard, as these go into the mast around 6-8ft off the deck and exit near the top.

Never use external halyards – if the block at the masthead fails then you’ll be freefalling on to the deck.

For an alternative method of using two halyards, but only winching one, you can read about and watch the video of this safe method in our practical guide to climbing a mast solo and double handed. 

3 Get comfortable

Get in the chair and bounce in it just 
off the deck to ensure it is comfortable and adjusted correctly.

Tie bowlines through the lifting part of the harness.

Never rely on a shackle as this may come undone or fail.

Once you’ve done this with both halyards, you’re set to go.

4 Hoisting

Hoisting the person can be tiring work.

The person aloft can assist greatly by pulling themselves up, but care must be taken to stay safely in the chair or harness.

Keep three turns on the winch and a clutch closed on the primary halyard.

This halyard has their full weight on it at all times.

5 Safety line

As you’re hoisting, stop every couple of metres or so and pull in the slack of the safety line and secure.
See alternative double handed mast climbing method of using a prusik line on a static halyard made off at the mast base. 

should also be through a clutch and on a

If this is not possible, make the lead
 fair to a cleat and secure.

6 Secure aloft

When they are at the desired height, tension the safety line by hand and secure both lines.

On the winch, use a tugboat hitch and move away from the mast 
in case they drop something.

7 Flake the halyard

Flake the halyard

While they are up the mast, flake out
 both of the halyards so these can run free when they’re being lowered.

8 Lower away

A man being lowered down a mast

Lowering can be tricky unless you 
have the correct amount of friction
 in the lines – both primary and safety lines.

Ideally, the person being lowered would like to be lowered smoothly all the way down.

Having too much friction on the lines results 
in having to ease by hand on the winch, which bounces them all the way down.

The number
 of turns will depend upon the size of the winch, the make of the winch (some manufacturers’ winches have more friction than others), and
 the type and diameter of the halyard used.

It’s likely to be at least two or three turns.

A man helping to lower a crew member down a yacht's mast

Lower as smoothly as possible, always keeping an eye on what’s going on above you

Lower them hand over hand for the smoothest journey down.

The man aloft pulls through a couple of metres of one of the lines, the person on deck secures it, then eases the other halyard until both halyards are tight.

Repeat this process
 until they are on deck, keeping an eye on them all the way down.

Gear for going aloft

Well-chosen gear that will keep you safe and comfortable


A man wearing a helmet climbing a mast

A helmet can protect you from serious injury

A helmet is never a bad idea for going aloft
 when alongside or at anchor, but it is a must
 in any kind of seaway as one wave swinging 
you into the rigging could cause serious injury.

Lightweight climbing
 or kayaking models that also protect the side of the head are ideal but a bike helmet will also do.

Ensure the chinstrap is short and any excess is tucked in to prevent it getting caught in anything whilst aloft.

Available for under £25, a helmet is a worthwhile part of your boat’s kit.

For helmet options and other safety climbing gear we have a smart buyers guide. 

Mast ladder

A crew climbing a mast ladder

A mast-climbing ladder can be invaluable, taking the strain off the crew on deck. Credit: Colin Work

One popular addition amongst shorthanded cruisers to their mast-climbing kit is a ladder.

Available in various forms, they are particularly helpful in taking the strain out of getting someone aloft, allowing the crewmember going up the mast to gain purchase themselves.


A man using an ascender to climb a mast

A climbing ascender can be used in an emergency. Check that the model you are using is designed for the diameter of your halyard. Credit: Colin Work

Ascenders are an alternative method of climbing a single rope.

Ideal for singlehanded sailors, they can also be used 
in tandem.

This is a useful bit of emergency kit that can also be connected to your second line 
to provide a safety line that isn’t dependent on the crew on deck

Things to avoid going aloft

  • Never use a halyard that’s routed through
 an external block running outside the mast
  • Avoid old halyards and those showing any sign of chafing or wear
  • Shackles or quick-release karabiners 
should not be used. Always tie directly
 into the harness or bosun’s chair to
 ensure there is one less point of failure
  • Never go aloft in a harness that doesn’t
 sit tight above your hips

Bosun’s chair or harness?

The traditional piece of kit to haul someone aloft is a bosun’s chair.

Most designs have a central tie point that’s in line with the sternum when loaded.

Chairs are generally more comfortable than their harness counterparts, due to how they spread the load and the more relaxed seating position, ideal when you’re embarking on a big job up
 the mast that will keep you there for a while.

A bosun's chair

Even the most basic bosun’s chair is more comfortable than a harness

The chair you buy should be purpose-built
 for use on yachts and deep enough in the seat
 to ensure you feel safe and comfortable.

The work you are doing up the mast shouldn’t take you out of the seat as, unlike a climbing harness, a bosun’s chair won’t keep you secure if you end up inverted; most designs rely on the user’s weight to be safe.

If you are going to take your own weight out of the seat aloft, on a mast step or spreaders for example, be sure to use a harness.

Bosun's chair

More expensive models generally offer more padding and pockets

Chairs vary in design and suit different body shapes – be sure to try before you buy.

A pocket for tools, preferably with a flap
 to keep contents secure, is very useful.

 items you put in trouser pockets will probably 
be hard to access once in the seat, whilst drawing anything from a pocket that’s not vertically opening is asking for the item to be dropped.

For larger items, attach a bucket on a rope, ensuring it doesn’t interfere with the lines holding you aloft.

Simon Phillips wearing a fleece and a lifejacket

Simon Phillips has cruised and raced over 325,000 miles, including 34 Atlantic crossings

Anything dangerous if dropped should be secured with a lanyard, whilst heavy loads should be supported by their own halyard.

A climbing harness is the alternative option 
to a bosun’s chair, although they are less flexible on body size and it’s crucial that the harness fits; climbing harnesses are designed to hold the wearer secure above the hips.

Allowing more freedom of movement in exchange for less comfort, harnesses are ideal for going up the mast at sea.

Some professional models secure the upper body as well and even include a seat that can be dropped down when in position aloft.

Both harnesses and bosun’s chairs should 
be stored clean and dry to prevent degradation of the material.

If you enjoyed reading this, you may also like:

A buyers guide to mast climbing gear and practical expert method for single handed mast climbing

7 mast climbing kits on test

12 Bosuns chairs tested

How to climb a mast safely at sea with Pip Hare

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