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A subject that I have been giving a lot of thought to these days is jacklines. For those of you not immediately familiar with that term, jacklines are pieces of line, webbing or wire that typically run the length of the boat, and are secured to strong, fixed points. The theory is that when attached to one of these lines via your harness/tether, you can move about the boat safely, and hopefully, if you slip, or are hit by a large wave, they will prevent you from being lost overboard. The physics behind this is not quite that simple though.

Just yesterday I read an article that, following the 2011 death of a yacht skipper who was dragged to his death after falling overboard, expanded on the problems of what happens if the jacklines do not keep you on the deck. The title of the article, Is it safe to use a tether?, implies that there may be circumstances where not being tethered to the boat might be better. Personally, I can’t see it. The article is good though, and it covers a lot. It is well worth reviewing!

An image of a jackline setup that I found on the net. Would this keep you on board? Not likely!
Note that the tether in the image also appears to be made of non-stretch Dyneema, something that is very much debatable!

Our friend Drew, an experienced sailor and rock climber, has given this subject a fair amount of consideration. If you search his site you’ll come up with several posts dedicated to the topic. The guys at Attainable Adventure Cruising have also been posting some excellent research on the subject. You’ll need a membership to their site to read the articles though. For the record, that is something that I do believe is worthwhile if you have a few dollars to spend.

The challenge with all this is that while some of the findings from this research can easily be adopted, each boat is different, and thus requires some adaptation to create a workable and safe system.

What needs to be determined?

  • Where should the jacklines be run?
  • To what should they be attached?
  • What material should the jacklines be made of?
  • What material should the tethers be made of?
  • How long should the tethers be?
  • Should you use a dual ether system?
  • If not a dual-tether system, should you have remote tethers placed at points on the deck?
  • What type of connector on the tether (snap shackle, carabiner, etc.)?
  • Should you use an integrated harness/PFD?
  • How should you use the system to move about the boat safely?

I’m sure there are other points to consider too.

Do I have any answers to share yet? None whatsoever. Rest assured though that when I do come up with a solution, I’ll share it here.


  1. After reading some of that information a couple of years ago I now run my jackline as close to the centerline of the boat as possible.

  2. This is something I’ve often wondered about as well, and letting the imagination wonder, what would happen if you were on a solo passage and swept over the side and unable to pull yourself up. Ideally there has to be a way to get back into a moving boat, especially in rough seas. Possibly a safety halyard setup, whereas you can hoist yourself back up the side? Alternative thought, perhaps your tether should never be extendable past your safety lines at any point on the boat.

  3. We’ve been doing some thinking along these lines too. And one thing that we keep coming back to is that high lifelines with netting may be at least as important for staying on the boat (this said by someone with a boat that has only 24″ lifelines . . .). Also things like developing balance and wearing clothing that doesn’t restrict movement.

    And we just recently re-routed our jacklines so they go even closer to the centerline than they had.

    Looking forward to seeing what you come up with.

  4. We have jacklines in the cockpit and on deck. We set them up once. Then we came to the realization that were not those kind of sailors, who take long passages in potentially risky weather. I applaud your stamina and fearlessness for anticipating such passages and preparing appropriately.

    I think that the trick is to keep the tether short enough that if you are swept overboard over the top of the lifeline your feet may dangle in the water but enough of your body is suspended that you can pull yourself up by grabbing a stantion

    Lynn and Larry, suggest running a line from the stern to the bow, tied around each shroud at crouching shoulder level. That line becomes an extra hand hold to help you stay aboard.

    Best wishes.

  5. I spent a lot of time reading Sail Delmarva’s posts on this topic before installing backlines on our boat. Ultimately, I ended up buying a bunch of webbing and carabiners from REI and created my own tethers, rather than paying too much for something “boat specific” that would have been nowhere near as good anyway.

  6. There is a product that gives you a better chance of getting back on board when you are being dragged alongside your boat. Here is a video demonstration:

    • That’s a really interesting contraption.

      I always was more worried about going off the boat in more severe conditions AND at night AND where I might not have the proper use of both arms and legs. I concluded that the best solution was one that kept me on the boat if I were knocked down.

      For this reason, I used dual tethers (one long and one short) and ran the jacklines along the roof of my catamaran. The longest portion of the tether allowed me to reach (just barely, in some places) all the important spots without allowing me to go over the side.

      For Mike and Rebecca on Frost, that may not be a viable solution.

  7. Mike, thank for initiating this discussion. As a result, we can consider ahead of time the placement of backlines, styles and number of tethers, and what to do if going overboard without someone to assist you getting back aboard safely. I’m not widely experienced in the use of backlines, only needing them on three occasions, and not having fallen overboard when clipped on. But depending on what I was doing, and where I was on the boat, I used backlines that were routed very differently. If I’m working at the mast, I like to have my backlines cross just before the mast. When I needed to be clipped on while servicing a jammed jib fuller and a catamaran, I preferred to be clipped to a jackline run between two bow cleats. When I had to go overboard to clear a line wrapped around one of the cat’s propellers while underway, I tethered to the shortest backline I could manage, attached to the stern cleats.

  8. I would add that the carrabiner sucks.
    a. Not locking. It is not just that it could come off. They also have a way of clipping other lines they slide over. Imagine being clipped to a wild jib sheet!
    b. Lousy SS biner with snagging gate. At least use a smooth-gated wire gate biner.

    I posted my opinions on jackline materials, after considerable testing, on Practical Sailor. The conclusion was that there are no one-size-fits-all solutions. Longer jacklines must be stronger and lower in stretch, which I think is obvious. Whether Frost has long jacklines depends on whether they are continuous or break at the center cockpit; I don’t know about that.

    Personally, I prefer strong, low-stretch jacklines paired with stretch tethers. But the latter product is not commercially available. The advantage is that you still have the advantage of shock absorption when clipped to a hard point. The only documented failures have been when the sailor was clipped directly to a hard point.

    I also like one VERY short leg (<2') for work in bad places. It also has the advantage that when the short leg is clipped up, it is barely noticeable. Also, a 6' leg can be doubled around the line or hard point to give a 3' leg.

  9. And if you clip the spare tether to your harness you defeat the quick release feature, if applicable. That failure contributed to one fatality that I know of. You need a parking spot on the tether itself.

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