internationally accepted certification

scuttlebut blog

Keel Failure and the Deadly Inversion

Jul 20, 2017

Author: Fin

Fintan Hartnett is the Principal and Chief Instructor at Topmast Maritime Training and an RYA Yachtmaster Instructor as well as Sail Canada and ASA instructor.

A Bad Day at the Office

The Old Salt Blog recently posted a slightly inflammatory but informative piece on keels falling off (here) which raises more questions than it answers.  Whether or not the few tragic incidents require an overhauling of design specs or engineering standards is something which could drag on for a long time in the world of cost/benefit analysis.  Regardless, it happens and it does require more discussion from a safety perspective.

Is there a proactive answer?  Well, do you ever pull up the floorboards and have a good look at the keel bolts?  Even if you do, do you know what to look for?  Here’s the rub – unless it’s really obvious (major cracks, loose nuts or severe rust) there’s not a surefire way to be 100% the keel is 100% without expensive structural testing out of the water (though when the boat is out of the water on the cradle it’s a good time to have a close look at the keel).  For the most part we just have to assume the engineers got it right.

But is this the crux of the problem?  No.  The real issue is the subsequent inversion after keel failure, which can, and often does, prove deadly.

If you happen to be caught down below the biggest danger is likely going to be everyday items which aren’t secured flying around the cabin, including yourself.  If you want a better idea of what goes on then check out this controlled test done by Yachting Monthly in a controlled environment.

Anyone who has had a look down below after a bad broach or knockdown can attest to the resulting mess.

All the more reason to make sure everything (and I mean everything!) is stowed in a manner which doesn’t allow it to become a deadly projectile.

If you’re down below and awake as you invert then hopefully you have time to brace yourself or grab onto something to break the resulting fall without breaking yourself. If you’re asleep then hopefully the lee cloth is in place, if not…

Cheery stuff isn’t it? I’ll deal with what do when you’re trapped in an inverted hull at sea at a later date (you can get a head start by reading about Tony Bullimore and the 1996 Vendee Globe).

If you’re outside and you’re not clipped on then things are pretty academic. Needless to say, staying close to the upturned hull is paramount. Being clipped on can lead to its own nightmarish issues, including being trapped underneath the cockpit (a quick release tether and a knife are useful here). If you’re lucky enough to emerge unscathed then let’s hope you’ve put some thought into life-raft placement.

The best position (which is not always feasible but should be a standard feature on new production boats) is to have a rear mounted life-raft on a hydro-static release. Unless you plan on inflating it inside the boat there’s not much point in it being down below – but is that the worst idea ever? As long as the tubes aren’t punctured while inflating then you’re just adding buoyancy to the upturned hull which may be a good thing. Having automatically inflating air bags in boats may be a better idea. I would much rather be under a rigid hull in bad weather than in an exposed life-raft.


Dark upturned hulls are hard for aircraft to see. Think about a lighter colour of anti-fouling or investigate the possibility of using retro-reflective tape at the waterline or on the hull itself (if it will stay).

If it all sounds pretty bleak then that’s because it is. If only it was possible to keep the keel from detaching completely so as to prevent the inversion in the first place. This may not be as far-fetched as it sounds. It is possible to build a fail-safe device attached to the keel and a secondary strong-point on the vessel, perhaps attached by strong wire. Is this practical? Maybe, but I’ll leave this expensive sounding solution to the engineers.

Where does this leave us? Try your best to be prepared. Take time stowing gear properly. Think through the placement of the liferaft and EPIRB, check the keel bolts regularly, use a quick release tether and carry a knife.

One last thing, to echo something I wrote in a previous post, helmets in bad weather or at night might be a way of keeping your head on. When things are bashing around protecting the brain is going to make that crucial decision-making process a lot better.

COVID19 and Sail Training (Updated: Jan 2022)

Topmast is committed to conducting courses in a safe and responsible manner to ensure the health and safety of our students and Instructors.

RYA Training Centre

%d bloggers like this: