20 Things I Have Learned About Person Overboard Prevention


Just three years ago I thought I really understood Person Overboard (POB) Prevention, to the point that I wrote several posts describing our system. And then, as part of that process, I found out just how little I really knew, and how many of my cherished ideas about what would keep me and my crew safe were just plain wrong.

That realization started Phyllis and me on a project to improve our POB gear and procedures.

We are now out sailing, have been testing our new system, and are finally satisfied that we have not only reduced the chances that one of us will be lost overboard, but also come up with a substantial improvement on the standard gear and procedures used by most offshore sailors.

And better still, none of these changes have made us any less efficient in handling our boat; in fact, rather the opposite.

Over the next few months we will be publishing new and updated chapters in our Person Overboard Prevention Online Book detailing this season’s changes and improvements.

But before we do that, I thought it would be useful to publish a short overview post to get us all back up to speed, particularly since I have not written on this subject in nearly a year, and some of you may not be aware at all of the work we have done on it to date.

I Have Learned That:

  1. The regulations developed for POB prevention by ocean race regulators are deeply flawed, particularly when applied to short-handed cruising crews, and should not be relied on.
  2. The offshore sailing community places far, far too much emphasis on recovering a POB, and not enough on making sure that no one goes overboard in the first place.
  3. The chances of a short-handed crew recovering a POB offshore are way less than 50% and, if it’s blowing hard or dark, approach 0%. Note that every POB recovery practice video is made inshore in smooth water, good visibility, and benign conditions for just this reason—losing people in drills is a bad idea.
  4. Being attached to the boat at all times, without the need to unclip and reclip while performing sail handling functions, is vital.
  5. As several recent tragedies have shown, drowning by being dragged on a tether is a far bigger risk than most sailors realize.
  6. Self-rescue while being dragged is near-impossible.
  7. It is difficult or impossible for a short-handed crew to recover a person being dragged (recent deaths have tragically proved this).
  8. Tether arrest shock loads are far higher than most sailors realize—as  much as a ton or more in comparatively short falls or while being dragged—and can kill or maim.
  9. Most jackline systems are useless and may even be more dangerous than no jacklines at all since they confer a false sense of security.
  10. Low-stretch jacklines made of Spectra or wire are a very bad idea because they increase shock loads, can break due to the geometric load multiplier, and don’t eliminate drag risk.
  11. To be safe, jacklines and tethers must be arranged in such a way that the tether end attached to the crew’s harness can’t get closer than one foot to the toe rail.
  12. Centreline jacklines are the only viable way to solve the above problems.
  13. On our boat (and I suspect most boats) a centreline jackline system can be designed that allows efficient working of the rig while still solving the problems above.
  14. The crotch straps on harnesses and lifejackets sold in the marine market will fail under tether arrest loads and therefore should not be relied on.
  15. It is vital that harnesses have easily adjusted chest straps and that crew learn to always adjust said straps so they are tight after every change of clothing bulk.
  16. Falling as little as 2 feet while attached to a hardpoint with a typical tether can result in chest crushing loads.
  17. Tethers made of high-modulus materials, like those we are now seeing in marine stores, are a very bad idea and potential killers.
  18. Attaching to a jackline is safer than a hard point because deflection of the jackline reduces impact load.
  19. Tethers that will be attached to hard points should be made of high-stretch materials.
  20. In the quest to reduce the risk of a POB tragedy, an open logical mind free from the dogma of “we have always done it this way” is our most important asset.

Wow, quite a list. I’m guessing that many of you who were not part of our three-year project to learn the above are shaking your heads and assuming that I’m some kind of cracked safety nut.

In fact, you are probably ready to close your browser window and go read about something fun. I don’t blame you. Three years ago I would have left too. But if you care about your own safety and that of your loved ones, don’t.

I didn’t make this stuff up, rather it is the result of the combined wisdom of voyagers, engineers and climbers expressed in hundreds of comments to my earlier posts on the subject. A huge thank you to all of you who contributed.

Phyllis and I then took that information and spent hundreds of hours thinking and experimenting before coming up with a better system.

If you are new to this project:

I strongly suggest you start at chapter one and read through to the end. Yea, I know, you are busy. Fine, but are you comfortable saying that “I don’t have less than an hour (that’s all it will take) to invest in my loved ones’ safety?” No, didn’t think so.

If you were part of the project from the beginning or came in at some later point:

I suggest you read through the Online Book Table of Contents to make sure you are up to speed on all the above points.


I considered publishing this post with the comments closed because I dread spending hours covering subjects that we have already done to death. In the end I decided not to take that path. Please confirm that I made the right decision by at least scanning the contents of the Online Book and reading the relevant chapter before commenting to make sure we have not already covered the subject of your comment.

Please Share

One more thing. This is important stuff, please share this post by using the social buttons below, it really helps get the word out.

And if you are thinking that you won’t share because this post links to paid content, ask yourself  these questions.

Do you never recommend:

  • a restaurant because the food is not free;
  • a book because it costs money to buy;
  • a movie because it is not free;
  • a great boat mechanic because he or she charges a fair price for their time?

OK, I will stop, you get the idea. Please share. We need the support so we can keep doing this work.

Like what you just read? Get lots more:

Learn About Membership

Notify of
Inline Feedbacks
View all comments