Scaling The Mast Without Support Staff

Today I tested my new ATN Mastclimber for the first time, successfully completing the first of two planned trips up Mobert’s mast, working to take care of a few small fixes.

It took a few minutes to analyze the instructions, fit the ascenders onto the spinnaker halyard and start going.  And it’s pretty slow-moving, but it works–and surprisingly it feels pretty secure.

I made it up about halfway, past the first spreader to the radome and other nearby fittings.   Coming down takes some practice because you can’t move the ascenders too far each time or you can’t move the next one because it still has too much pressure on it from your body weight.

While I was up the mast I accomplished the following tasks:

  • Replaced the cracked lens on the steaming light
  • Upgraded the deck floodlight to a LED Flood bulb.  It should be almost 3 times brighter than the non-LED bulb it replaced and use 1/4 of the energy.
  • Removed the useless TV antenna mount that we put up 2 years ago.  Unfortunately the antenna itself won’t stay on the mount, so it has fallen off twice, the second time it was not recovered.
  • Removed a sample screw from the lower spreader so I can get more screws and replace a missing screw on the upper spreader.

Unfortunately the new screws don’t come as short as the screw I removed, so I’ll have to cut the screws down at home before I go back up the mast and re-install them.

I also have the Spinlock Mast Pro Harness and I’ve gone up the mast a couple of times using that harness, with Devon at the winch controlling the halyard.

In comparing the ATN Mast Climber vs. the Spinlock Mast Pro Harness I have a few thoughts..

ATN Mast Climber: (~$450)


  • Can climb the mast independently, without any help from other people
  • The bosun’s chair included with the full Mastclimber kit is pretty comfortable
  • The included storage bag clips on and doubles as a tool bag
  • Can stand up at the top to reach over the masthead


  • By nature it’s pretty slow to move up and down the mast
  • About 3X more expensive than a harness or traditional bosun’s chair

Spinlock Mast Pro Harness: (~$150)


  • Very secure
  • Less Expensive
  • Easy to use
  • Comfortable


  • Can’t climb the mast independently, need at least a second person to handle the lines
  • Very difficult, if not impossible, to get up over the top of the masthead

All that said, you could use the ATN Mastclimber as a traditional bosun’s chair with a halyard lifting you.  And you could attach the upper ascender to another halyard as a safety if you wanted.  Despite it’s 3X cost over the Mast Pro Harness and other bosun’s chairs, I think the Mastclimber is definitely more versatile and worth buying.

If you happen to love your Spinlock Harness (or other Bosuns’ chair) you can buy the Mastclimber “kit” from ATN for $275 and convert your chair/harness into a Mastclimber.



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