The Offshore Voyaging Reference Site

Jonbuoy—Stuff That Works (We Hope)

The winter we spent in London England living on Morgan’s Cloud at St Katharine Haven next to Tower Bridge, was wonderful. We walked all over the city and soaked up the history and culture. And the pubs…wow!

While there we took our MOM and liferaft to Ocean Safety to be serviced. They were great—they inflated our liferaft and let us see how everything worked, always a good idea.

A New Option in MOB Recovery

The other thing they did was condemn our MOM, since the fabric had failed. They suggested the Jonbuoy Recovery Module as a replacement; at the time a relatively new option, which they had developed. The Jonbuoy has a tall inflated mast, which not only makes it easier to see in the water compared to a lifering, it has a lifting ring on the top of the mast so that the MOB can be easily raised on deck with a halyard. Also, the mast is integrated with a teeny liferaft that the person in the water can climb into, an added benefit in cold water.

11 Years Later—A Replacement

The Jonbuoy that we bought in England in 2001 was just condemned this winter during service, not a bad lifespan for equipment that lives on the rail full-time. So we replaced it with another Jonbuoy from LRSE, the US distributors, another great company we’ve worked with over the years to service our safety equipment.

A Pre-emptive Strike

Now, I’m going to do some pre-empting here! Yes, we have a Lifesling attached to the aft rail, next to the Jonbuoy, which would be deployed together with the Jonbuoy. That way the person in the water will be able to choose between the Lifesling, which is attached to the boat, and the Jonbuoy, which has the benefits I described above.

No, we don’t have a Danbuoy. It seems to us that the inflatable Danbuoy falls between the Lifesling and the Jonbuoy—it’s not attached to the boat but neither does it have a lifting ring or the option for the person to get out of the water. And the rigid Danbuoy, together with an associated lifering, takes a long time to deploy, which is particularly problematic for a shorthanded crew, and is easily tangled on its way overboard (firsthand report from John based on many MOB exercises over the years).

A Best Chance Scenario

My greatest fear is that John will fall into the water someday, it could even be in an anchorage, and it’ll be up to me to get him back. It seems to me that, given a scenario in which he’s not able to help me (only a few minutes in cold water can be incapacitating), getting a halyard clipped onto the lifting ring on the top of the Jonbuoy’s mast, which should be close to deck level, would be a lot easier than trying to attach to the ring on his lifejacket, way down at water level. If, god forbid, he ever does hit the water, I want the best chance possible of getting him back on board with me…where he belongs.

Do you have personal experience with any of this MOB recovery gear (through practice or in anger)? Please leave a comment.


LRSE kindly gave us a slight break on the cost of the Jonbuoy of $100.00. Not enough to influence our feelings about the Jonbuoy!

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Dick Stevenson

Phyllis, We are a live-aboard cruising couple who are usually on their own and always on our own on passages. Our Lifesling has been used in MOB drills where each of us jumps into the water (in wet suits and with others on board in observer status) and is “recovered” singlehanded. Once you know your boat’s handling characteristics (not necessarily intuitive as we rarely ask our vessels to pirouette), Lifesling fulfilled its advertised promises. We sail with a MOM also, but I have been considering a conventional rigid Danbuoy because of the frequency of reports of inflation devices not working. (Our MOM worked perfectly in a practice deployment just before a re-packing).These reports are mostly anecdotal, not overwhelmingly numerous, but worrisome. A rigid Danbouy system would be more of a headache to store and deploy (my boat is significantly smaller), but would easy my mind about reliability. Jury still out. BTW, we are at St. Katharine Docks (Haven) for this winter and loving it.
Dick Stevenson, s/v Alchemy

Dick Stevenson

Phyllis, Follow up on previous. Getting an active MOB back on board is work but not a big worry. Getting someone unable to help him/her self is more than likely not going to work out. We have a variety of methods worked out, but feel that all of them rely too much on good conditions and luck. We choose our boat behaviors with the idea that if underway and you fall overboard (get separated from the boat), you die. We will work hard to prove that a false notion, but try to operate with that in mind as a truth. Dick

John Harries

Hi Dick,

We could not agree more, great wisdom.

Even with an active MOB, add a dark night, cold water, and anything more than 20 knots of wind and the chances of recovery get very slim indeed.

When we do our MOB drill, in the introduction I always tell the crew to imagine that there is a 500-foot drop on the outside of the lifelines.

In fact we put a lot more effort into staying aboard than we do MOB recovery. Note to self: must do a post on that.


I memorized your “What Really Matters” list the first time I saw it 4 years ago. #2, of course: “Keep the crew on the boat.”


We sail shorthanded, wife and man (mars the 8’th is closing up), and in our world there are two kind of MOB.
One where the MOB is spotted as it happens. The chances of recovery should be quite good, that is if the MOB are afloat and the other part is able to maneuver the boat. The items mentioned are all helpful, some way or another, but we still think the two keywords here are: always wearing a LIFE JACKET and the both of us must be able to HANDLE THE BOAT. These are easy things to fulfill, or at least should be.

Worse; MOB without being spotted, like during night time when the other is down for a sleep. In this situation Danbouy, Jonbouy, Lifesling, Liferaft, whatever, none of them will be any good, and none of them will ever save your life, as long as your mate doesn’t know what’s going on.
The only life saver I know of being able to save my life, having this unpleasant and most unwanted swim, is my mate and without her present, all those other items are useless.
What are your tactics here?

Stafford Keegin

Might I ask you who made your drop down ladder that can be deployed from the water and are you pleased with it? Ever had to us it?

Many thanks.

John Harries

Hi Stafford,

The drop down ladder was made my Ibas Manufacturing, but I believe they ceased operation some years ago. I bought it back in 1994 when I was still doing quite a bit of single handed sailing, much of it in locations with cold water. My thinking on fitting it was that it would help me get back aboard unassisted if I fell in the water with the boat stationary, say in an anchorage, when I would not be wearing a harness and life line. And no, I have never had to use it, I’m pleased to say.



question on the Jon Buoy. If you through a Jon Buoy in heavy whether, I would guess that the Jon Buoy would drift much faster than a person could swim trying to reach the Jon Buoy, as the buoy has much more wind drift by way of its construction. Wouldn’t this fact render the Jon Buoy (or any other similar construction) more or less useless?


John Harries

Hi Klaus,

First off, recognize that this post was written some years ago before our POB strategy had evolved to the point it has today.

Second, the Jonbuoy has a ballasted pocket that will slow down its rate of drift quite a bit.

Third, I think you are probably right, the chances of a POB getting to the Jonbuoy, or any similar device are pretty small. That’s one of the many reasons that our POB strategy is primarily focused on not going overboard in the first place.

That said, the Jonbuoy is still useful. For example, should one of us fall in, even in an anchorage, in cold water, the Jonbuoy might really help, as detailed in the post above.