Climbing the
sailboat mast

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This page updated: September 2012

Climbing methods:

Mast steps:
From David Simpson on Cruising World message board:
I installed "Mast Walkers" ten years ago. They are what ABI copied to make theirs. Feel very comfortable and secure on them (with climbing harness and halyard tended by my wife). When folded, they rarely snag anything, and are vibration-free when motoring. The only down-side I can find is the weight aloft.

From Dave George on Cruising World message board:
We have permanent mast steps. This is a 50' (above deck) two spreader mast. My wife and I sail double handed, there is no way she could hoist me up the mast in a bosun's chair just with a halyard winch. I made my own steps out of aluminum strap, and had them anodized. I have attached them to the mast with machine screws in tapped holes. 18" apart is what I used, and is about right. I have two steps opposite each other right at the top, so I can stand up comfortably to work on things up there.

I have also run a light stainless cable along the outside edge of the steps to keep halyards from getting hung up. That works well.

I use the steps regularly. It is very handy to be able to run up and down to the first spreader to aid in navigating through reefs. Going above the first spreader I always use a bosun's chair and a halyard for safety, which my wife tends on the winch, but I climb the steps.

One thing we make a habit of is a full visual inspection of all rigging fittings all the way to the masthead before any kind of an offshore passage. The steps make it easy, without them I would be looking for excuses not to have to go up the mast, or looking for someone who could winch me up.

I am sure they add additional windage. We sail a medium / heavy 44' boat. A little extra windage on the mast is the least of our worries. On a smaller boat, windage might be a consideration. In our case the convenience far outweighs anything else.

About removable mast steps, from David Simpson on Cruising World message board:
The problems I see here: you must have some sort of bag to hold these on the way up and down ... must install and remove one-handed (both righties and lefties) ... When raising the leg to take a step, it is VERY easy to kick the step up and out and gone, and it will not be there any more for the trip down.

From Evert Volkersz on the WorldCruising mailing list:
... Fastep mast steps, which can be inserted in pre-drilled holes in the mast. The idea of going up the mast with a number of steps that need to be inserted while you are bobbing back and forth, or pounding, does not appeal to me. At the Atlantic City Boat Show Alfred Gilbert, the inventor, said I would probably make two trips just to put them all in. And I suppose two trips to take them all down, hoping that none fall on deck or in the water.

From John / Truelove on the WorldCruising mailing list:
I installed the ABI folding steps and I'm very happy with them. Damage Control makes a similar step, except they come in different "sizes" to fit various mast diameters. I used 1/4" aluminum rivets - be aware that two lengths may be required as the thickness at the bottom holes is less than at the top. I was careful to punch the steel mandrels out after riveting, and sealed the holes with silicone. I originally contemplated doing this job "in the air," and was happy that I did it with the spar on the hard instead. It's a good idea to measure clearances to shrouds, etc prior to unstepping the mast in order to avoid interference near the tangs. I had to offset a couple of steps in this area to provide clearance. Regarding spacing, I used the minimum recommended (18") because my 1st mate was short; I was happy I did, because although I'm 6'+, I would not want it to be greater than that.

From Jan Bruggeman on the WorldCruising mailing list:
I placed mine 1 m apart, but "out of phase": the ones at starboard sit just in the middle of the 1m space of the port ones. But that's something you'll just have to try for yourself. Important things are:

- choose a model in which you stick your feet "into them", and not "rest upon".

- mount 2 steps at equal height in top of the mast, so you can rest on both feet when fixing something in top of the mast. Somehow, the trouble is always at the top of the mast - except when the mast has been taken down, then the problem will be inside the mast ;-)

Mine are homemade: just bend some strips of stainless steel or aluminium and bolt them to the mast. Rivets didn't last.

Climb rope using ascenders or rachets:
From GeorgeB on Cruising World message board:
I've got the Topclimber; once you get the rhythm for moving your arms and legs it's fairly straightforward. However, the effort is still the equivalent of climbing several flights of stairs.

From Doug Sterrett on the WorldCruising mailing list:
[Re: ATN Topclimber:] No offense to ATN but I priced the components used in this set-up at my local rock climbing shop and came up with $175 instead of ATN's $280 (with inferior ascenders). Go buy the pieces yourself (get Petzl brand ascenders) and save yourself some money. Cautionary note: Try this rig out hanging from a rafter in your garage before you go up your mast. It takes a little learning to get the knack of it.

From Bob Foco on Cruising World message board:
My son is a mountain climber and gave me 2 Gibb ratchets. They are like a cam cleat (but obviously safer and a bit more sophisticated). They cost $40 apiece.

The first thing you do is attach the main halyard to the base of the mast and tighten it bar-hard. Attach the 2 cleats to the halyard, one lower than the other. Attached to the top cleat is a climbing harness or bosun's chair. Attached to the lower cleat is line with 2 foot-loops.

STEP 1 - You simply sit on the bosun's chair and slide the lower cleat up until it hits the bottom of the upper cleat. This can be done because there is no weight on the foot straps.
STEP 2 - stand up (which takes weight off the bosun's chair) and slide the upper cleat up the halyard.
STEP 3 - repeat STEP 1.

I have a 62-foot mast and go up and down it easily to spray my sail-track, inspect shrouds, or do other maintenance. They can be purchased at REI or any mountain shop.


The gibb ascender is "cleat-like". One end of the cleat is a jaw and the other end is a lever. When you want to come down you lift the lever which withdraws the jaw. This can only be done when there is no load on that particular ascender. If the ascender is loaded (weight on) then it is "impossible" to lift the lever. I use 2 ascenders, my harness is attached to the top one and a "texas tee" foot strap is attached to the lower ascender. Advice from Al Hatch says to run a safety strap from the harness to the lower ascender also.

My experience so far (6 climbs):
I put together an equivalent of ATN TopClimber from parts (ATN's is slightly more expensive and I've heard their bosun's chair is not good).

Nice bosun's chair from SailNet ($75), small pieces of line ($10), 2 quick-links ($8), rest from onrope1: 2 Petzl ascenders (2 x $45), foot loops ($45), simple safety harness ($32), 60 feet of climbing line ($36). Total $310 with tax, shipping.

I wish I'd gotten two right-handed ascenders instead of one right and one left. I find it easiest to hold the mast with my left hand and work the ascenders with my right hand.

From Tim O'Neil on the SailNet liveaboard-list:
For what it's worth, I was extremely discouraged with my ATN self Climber. If you want to inch up your mast (it takes forever) plus struggle with poor design of the handheld unit (after several feet up my right hand was deformed and very sore), buy it!! By the way, I jog daily so my legs were up to the task.

I'm back to a static / safety line and my mate yanking me up on the main grinder in the ATN chair and harness. I'm sure other "rock climbing systems" are more effective.

My experience:
I made a climbing rig with ascenders and a bosun's chair and foot-loops (pics). It works fine.

But getting anything done at the top of the mast is frustrating ! I don't get quite high enough on the spare halyard, there's only one mast step to stand on at the top, stays and shrouds get in the way, I often need one hand to hang on and two more to use tools, standing up there in awkward positions and holding on is tiring, and most of the 30-year-old hardware at the top of my mast is frozen/galled in place.

Ascenders from REI

From Ron Rogers on the SailNet liveaboard-list:
... these devices [ascenders] eventually chew the outer layer of the rope. They were intended for use with kernmantle/braided rope with an abrasion-resistant outer shell ...

From Rob Patt on World-Cruising mailing list:
Do not connect ascenders on the main halyard! Ascenders eat ropes. In climbing we retire ropes more often than in sailing. When using the main halyard as a safety line tie it off with a figure eight, do not use the shackle, as this has been the most common failure point for accidents that have crippled or killed people climbing masts. We would actually use two halyards for mast climbing for a secondary safety; make sure there isn't slack that could create a fall distance. The person going up can take up slack if you are limited by the number of people.

From Al Hatch on Cruising World message board:
Ascender safety: Always have a safety line from each ascender to your harness. Falls usually happen on the way down, when you're tired, maybe cold, thinking you're almost safe on deck.

The safety line from each ascender to the harness should be short enough so if you end up falling onto it the ascender is still within your reach.

Self-hoisting with tackle:
From De Clarke:
... I splurged on a Mastlift, figuring it for a lifetime investment (it will get me up masts when I am 70 and doddering, I hope). It is a fine, though somewhat spooky, device. By "spooky" I mean only that when you are 30 ft off the deck and rising, there's a tendency to look up at that anonymous can and wonder how sturdy is the little pawl that is keeping you from falling down again :-)

I have been up a 37 ft mast three or four times with it, though not all the way to the very top. Though it was a heckuva lot of money (ouch!) it means that I can do mast work any time, on my own schedule, without needing some large and trustworthy gorilla to handle the halyard for me (I'm too old and fat and lazy to climb up the hard way, for sure!). I do have some doubts about using the mastlift in a seaway though. It tends to swing and bang about while being hoisted.

My technique for using it is not as the mfr recommends, of course :-) I find the little winding handle they provide to be absolutely useless either for winding up or unwinding the gizmo. What I do (so far) is attach a weight to the free end of the lifting line -- a 5 gal jug of water does fine -- and then hoist the whole shebang up. I use the "endless loop" hauling line to control the swinging of the unit as it goes up. When it gets to the top, the 5 gal jug gives me enough tension that I can just whale away on the hauling line to bring the business end down to deck level again. I find this much easier than trying to unwind the lifting line on deck and then deal with 40 ft of that plus 40 ft (doubled) of hauling line -- a real snake's-nest.

The disconcerting thing about this gizmo is the little hiccup when you reverse direction and start going down. There's about a half-inch or so of free-fall before the clutch bites firmly, and of course the first time this is a real adrenaline rush :-) but after a while I got used to it (OK, I still grit my teeth a bit, but at least I know what to expect). The very best thing about it is the enormous reduction (10/1 or so) which means it is slow but almost effortless to get 30 or 40 feet off the deck. I made two trips in one day, with a lot of drilling and futzing around at the top (installing lazy-jacks) and apart from the nervousness of working high up with unknown gear, I felt rested and relaxed at the top, rather than exhausted. And (dig this) it can be worked one-handed.

A buddy of mine bought the topclimber device -- the harness which allows you to "inchworm" your way up a taut rope using cam cleats. We both tried it out. We found that it was far more tiring to use than we had anticipated. I found it seemed more difficult for a short person -- something about the design of the harness and location of the cleats. The vendor claims it is "easy" and will not tire you out, but we disagreed after a couple of practice climbs. It is $310 if you recall -- not cheap, but less than 1/3 the price of the mastlift. We did not achieve a consensus on who got their money's worth :-)


The only bad thing I will say about my unit is that it arrived a bit rusty (the internal reduction gears). Probably nowhere near as rusty as it may get when stored on a boat for months, but it does warn me that regular maintenance with white-grease will be an absolute necessity for the "gearbox". I have not yet taken it apart :-) as I am somewhat afraid of breaking it and/or not knowing how to verify its function properly before trusting it again after reassembly.

So that's it for the mastlift -- ridiculously expensive, but it really delivers on the promise of near-effortless mast climbing and (after a little experience to win my trust) a feeling of security.

From Warren Johnson:
After having tons of work done by Brion Toss we picked up a great and simple system for going aloft. It simply involves using: Brion's safety harness (very comfortable -- I spent nearly two hours at the top of the mast drilling/tapping/installing a new LED tri-color before taking off, however it's pretty pricy), a single racheting block from Harken (need one that will take at least 9/16" line) and approx 110' (depends on your mast -- I went with more than I needed so I could help out friends) of 5/8" yachtbraid cordage.

To set up, you simply reave the 5/8" line thru the block and take it aloft -- one end of the line is attached to a carabiner (via a butterfly or becket bend etc) on the climber, the other (which should be lead through a carabiner on the climber so it won't get away) is used as the 'hoist' and should be flaked on deck.

The use of the above system is pretty self explanatory, just remember that you always have another 'safety' line as well -- this is not used to hoist (unless the climber gets pooped near the top etc) but is keep taut in case the other line fails and is not used to lower climber (they do that on their own).

Also, IMHO (and Brions' crew) it's a mistake to use a 4:1 setup for the block and tackle to get to the top of the mast -- too many lines to foul. 2:1 works FINE and you get a pretty good workout (I generally take a little break on my way up at the spreaders).

This setup fits very nicely into a large gym bag for quick deployment as needed.

From Richard Dixon:
I use my anchor winch with its long (14 m) cable with controls on. Easy as pie in my bosun's chair (home-made) and the mainsail halyard (max loading 750 kg), safety line is an abrasive rubber sleeve which locks around the mast (stages) and hangs going up ... very quick and very safe as the rope is around the winch rounded part not in the chain dep.

> you run the anchor windlass from the bosun's
> chair, or does someone on deck run it for you ?

I run it myself, mainly because the last owner put a 13 meter long thick cable on the up-down thing/box, that enables me to go up using the outer ring of the winch, and not the inner, which is formed to take a chain, the outer is like a drum with an edge, which takes rope/halyard around it ... the whole point being I am often alone on deck doing things. Only thing that is unsure (when alone), is the fact of the rope slipping off the side of the winch whilst turning.

> rope could slip or jam on windlass,
> or control switch could stick on or off.

Bosun's chairs, and harnesses:
From Michael Rich on the SailNet liveaboard-list:
... I have a bosun's chair, the board type, and find it very unsafe. You can slip out of this chair quite easily and I wouldn't recommend it to anyone. There isn't any secure feeling sitting in this type of bosun's seat. ...

Bosun's chair makes it hard to use your legs to help climb, and to protect from collisions.

Want hard-bottom, not soft-bottom, bosun's chair.

Use harness (instead of bosun's chair) from PMI or Roco Rescue ?
But Amanda Neal says they may not dry very well, and may corrode, since they are not intended for marine use.
Maybe Brion Toss's "Bosun's Harness" ?

Want your chair/harness knot low enough on the chair/harness so that when you get to the top, you can reach the masthead.

A downhaul tied to the bottom of the chair/harness can be used to minimize swinging around.

From Robert Hutchinson:
Any of the ascender-based systems count on the attachment to the climber's harness to be above their center of gravity. I once used a lineman's waistbelt while climbing a tree with Jumar ascenders. On my way down from a strenuous climb, I found myself losing arm strength, and within a few feet of the ground, slowly inverted, as the harness attachment was below my center of gravity. Hanging upside down looking at my buddies brought smiles to their faces and much useless advice, but had it happened sixty feet higher, there would have been little they could do to save me. Be sure to consult with an experienced climbing expert when selecting a harness, and give it a lengthy test at low altitudes.

From Robin Lidstone:
I go up a fixed rope to the masthead using Jumars (mountaineering stuff) and find the best bosun's chair to be my old paragliding "harness". It provides comfortable seating and good attachment points; an older and out-of-date model could probably be picked up through a paragliding club or magazine.

SailNet - Sue and Larry's "Working Aloft In A Bosun's Chair"
Mast-climbing article by Bill Springer in 7/2004 issue of Sail magazine
Article by Frank Lanier in 11/2008 issue of Latitudes and Attitudes magazine

From Seahwk on the SailNet liveaboard-list:
Anyone who has been in a climbing harness for any period of time, knows that some can be very uncomfortable after a short period of time. I suggest a padded harness will be worth its weight in gold by the time you come down. Also, it is nice to attach 1" tubular webbing to the ascenders, which form the foot loops. A "water knot" should be the only knot used in tubular webbing. Other knots may slip or come apart. Any time one is suspended in a harness, there should be a completely separate back-up safety line clipped into the harness.

OK, shocking news, it is recommended that your system should have a 15 to 1 safety ratio the best that I recall. In other words, a 200 lb. person would need a line and system rated at 3000 pounds minimum. I don't know what ratings the pulleys in the tops of mast have but I would caution all going up to not overload any system. I can only imagine the effects corrosion and even ultraviolet light has on components. The reason for what seems like an extremely high rating is the "shock load" which a system may experience if one drops suddenly. Picture 200 lb. free falling 5 or 6 feet and suddenly stopped by the system. I know you can't picture this happening when everything is right, but when something goes wrong, this could be the situation. Sorry if I sound pessimistic but I have gotten this way due to my profession over the last 25 years. I also feel anyone in a bosun's chair should be in a harness and clipped in with a completely separate back-up system.

These are only my own opinions and extreme caution should be used by all going up any mast.

From Larry Dill on the Morgan mailing list:
I know that many folks prefer climbing ladders to dangling from ropes, but my preference is to use the bosun's chair. Using ladders or mast steps requires considerable focus.

Disagree? You've never seen folks slipping on ladders? Look at that oft played tape of the invasion of the Davidian compound at Waco -- it appears that one of the BATF guys shot himself in the foot as his foot slipped whilst rapidly ascending a ladder. He probably never did THAT before, but, he was under unusual stress. I'll concede that in the cool of the evening when all is serene, climbing a ladder may be okay, but you may be required to go aloft in nastier conditions, under stress.

I like knowing that my hands are free (if need be). The chair gives me a great deal of comfort, and I can comfortably sit at the masthead for as long as I like (spent over an hour up there as night fell one evening last season -- nothing to it).

Some don't totally trust their halyards to carry them to the top. I dunno what is the maximum load my halyard experiences in heavy air, but I'll wager that my 200 lbs (with chair and a few tools) is relatively insignificant.

This brings up a nice question, methinks: Anyone out there know of anyone falling while using a bosun's chair due to equipment failure? I'll hazard a guess that any mishaps are a result of neglect or oversight, not from over-stressing equipment.

Last time I climbed an antenna tower, I had this uncanny realization that if I missed a grip, the descent might be rather brief. As I swayed at the top, I wasted much of my energy, applying greater force to my grip than was necessary. I'll concede, that if I were to spend more time aloft, I may become more comfortable hanging to a swaying mast, but acquiring such skill is not high on my list of priorities.


Though probably unnecessary, when riding a chair, I hang on and assist with my arms. At the top, I can attach a harness to the masthead, if I choose. I have never felt insecure on a chair (but have on a ladder).

As a bonus, with the chair, I typically swing out to the ends of the spreaders on the way down, and have a close look at all rigging, just for the heck of it (okay, maybe I do it just because it's fun).


From William Holbrook on the SailNet liveaboard-list:
[In the ATN TopClimber,] the main device used is a rock climbing tool, generally called a "jammer". The first ones were made by a company called Jumar, so many climbers call them "Jumar jammers". Probably the biggest sellers now are made by Petzl, a company with a long history in rock climbing.

I have a climbing harness and a pair of jammers (they are made in left and right for ease of use with both hands). I went to REI, probably the largest seller of climbing products, and got advice from a climbing instructor. My initial setup was just like climbers use; each jammer had a webbing strap with a foot loop, all hooked to the climbing harness. I would climb by putting my weight on one foot and sliding the other jammer up the static line as far as the webbing loop allowed; then I would climb one step by shifting my weight to the other foot and repeating the process with the alternate loop. Although experienced climbers may find this easy; for me it was tiring and difficult.

My current setup uses a bosun's chair and a five-part tackle with one jammer. I use a spare halyard to raise the upper block in the five-part to masthead, and tie off the halyard. I then attach my bosun chair to the jammer and the lower block in the five-part. The line running thru the jammer is the running line of the five part. I can then use the 5:1 ratio to raise myself up the mast. I pull one arm length on the running part with my right hand, and slide the jammer up with my left. The jammer then holds me while I move my right hand up the running part for another pull. Coming down, I hold the thumb lock on the jammer with my left hand and tail the running part with my right, If I move too quickly, or wish to stop the descent for any other reason, I just let go the thumb latch, and I stop instantly. I find this setup easy to use, and I can go up and dowm without assistance.

By the way, I used this setup while installing mast steps. Since my aim is cruising, I don't mind the windage from the steps. I still prefer the bosun chair setup for lengthy jobs, although I must use the steps for anything on the masthead (I can't get high enough in the bosun chair). When I go up using the steps, I wear my climbing harness and use a jammer on a static line as a safety measure; if the boat rolls suddenly, or I slip, I am held by the harness. I generally tie a loop loosely around the mast also; this prevents me from flying away from the mast in the event of a fall, etc.

A final word on the climbing harness: A climbing harness will hold you even upside down. A bosun's chair will not!!

After 8 years aboard, my thinking is:
Remove everything from the top of the mast, so you don't have to climb the stupid thing (except to fix rigging issues). I got tired of climbing to fix the anchor light every 6 months; now I hang an anchor light inside my pilothouse, which is much more visible to high-speed skiffs traveling at night.

How to choose which crew should climb the mast:
Important factors: