How To Lock Your Dinghy

by Casey Brooks

Everywhere you go people want to steal your outboard.

Here on the Rio Dulce we have a real problem with this.  Some places are worse; Venezuela is legendary.  When I was there on “Retriever”  in 1999, a yacht in the same anchorage had their inflatable with outboard stolen one night.

This particular dinghy was raised high on the boat’s stern in davits and was locked with half inch stainless steel chain.  The next morning the chain was dangling in the water and the dinghy and outboard were gone.  The “weak link” was the cheaply made in China padlock, which had been cleanly cut with bolt cutters.  The shackle clearly said “hardened.”  Yeah, sure.  Go back to the first sentence. 

People want to steal your outboard.  They don’t necessarily want to steal your dinghy.  The modus operandi of the thieves is to steal the dinghy quietly.  Then they can take it to a remote place or a convenient hideout where they have plenty of time to extract the outboard motor: hacksaws, grinders, drills, chainsaws, cutting torches, tactical nuclear weapons, whatever it takes.

The key point is to lock your dinghy to the big boat every night.  Strong places can be found on any boat: cleats, pad eyes, stanchions, enclosed bulwark chocks and davits.  The problem is finding a strong point in the average dinghy.  If it is an inflatable there are usually a couple of U-bolts through the transom, but these can be cut with quality bolt cutters.  They can also be hack sawed, which is slower and noisier.  These U-bolts can also be unbolted, of course.

On my launch “Jaguar” the nuts of the U-bolts have been fiber-glassed over to prevent this.  In my opinion the impregnable point should be where the motor attaches to the dinghy.  See the photo of my 15 HP attached to my launch. (Note the custom jaguar paint job by Jennifer.  She’d probably be willing to paint your outboard too. Talk with her at Mario’s swap meet.)

First, there is an aluminum plate that beefs up and protects the transom from the outboard’s bracket.  Through this bracket there are two 5/16” stainless steel bolts that go through holes in the Yamaha’s bracket.  Good, the outboard is bolted on.

Next, the clamp screws are tightened down evenly, and adjusted so that they are both turned inward and the holes in the handles line up.  Now a quality padlock goes through the holes in the two handles and the eye of the stainless steel cable.  The cable in the photo is 3/16” 1x19.  Another good choice is a vinyl coated lifeline wire, the largest of which is ¼” diameter 7x7 wire and measures about 3/8”including the vinyl jacket.  Get a piece at least 10 feet long and micro press an eye (with thimble liners) in each end. One eye locks to the motor and the other eye locks to the yacht.

In the photo you see a “Corbin” SS padlock with a hardened 5/16” shackle.  In our tests neither the cheap bolt cutters, Taiwan 24” with black handles, or the expensive one, a Draper high tensile 30” with red handles,  could cut this.  Likewise, neither one of the bolt cutters could cut the lifeline wire. They merely crush the wire and cannot get through.

However, proper cable cutters,  Arm wr10: 24” with red handles, easily cut this cable.  These cable cutters belong to Steve on Witch of Endor. That’s Steve at the workbench gleefully cutting things.  These cutters are very hard to obtain and we hope the “ladrones” don’t have them.

So the “weak link” at the motor is the light aluminum clamp handles.  These can be easily broken with a hammer or a machete.  This happened to me once in Borneo, but the noise woke me up and I was able to foil the robbery.  Once the handles are broken, the cable with lock intact will fetch up on the eye built into the transom clamp pad – that is if you have one and have thought to thread the cable through it.  This eye is also aluminum and can be easily cut or broken, but more time and more noise is needed.

The handles can also be protected by a tube or bar lock, I do not particularly like these.  First off, there is not enough room to get the eye of the cable locked inside.  Secondly, these are merely painted steel, which rusts badly, and the lock (Master) needs oiling and cleaning frequently.  Many a boater has had to employ his or her safecracking skills when the frozen lock refuses to open.

I see that West Marine has a new version of the bar lock out in all stainless steel.  Called a “high security outboard lock” which sells for $100.  It’s worth checking out.  Greg and Barbara on C Toy showed me an elegant lock of this type, all stainless, made in Holland, which they bought for about $70.

Now, maybe this is overkill, but in addition to the cable at the motor, I lock up my launch at the bow with a chain.  In the photo you see me attacking this chain with the bolt cutters.  The Taiwanese black handles, probably equal to what you can buy at the hardware store here in Guatemala, couldn’t cut it, leaving only little beaver teeth marks.

The bigger, 30” Drapers cut the chain, but only with full body weight and bracing one handle on the hard surface of the launch.  With an inflatable and using only arm strength – I don’t think so.  This chain is 3/8” proof coil. High test would be even better.  However, one has to cut the chain twice to free the link.  Again, twice the time and noise.

This chain should be padlocked to the dinghy and the yacht with quality padlocks.  The round shaped “Diskus” padlock is excellent, as is the “Abus” # 89511.  These locks have high shoulders and no room to let bolt cutters or hacksaws get at the shackle.  Expect to pay at least $50 US for a good padlock.

On the big boat end, loop the chain through several places if you can.  I go around two shrouds and a lifeline stanchion.  Don’t use cheap Chinese made locks.

Using the black handled 24” bolt cutters, we chomped easily through a brass “Abus” lock with a quarter inch shackle.  Then we tried a “Globe” lock with a 3/8” shackle marked “hardened.”  The cheap bolt cutters couldn’t cut it, but the 30” Drapers could.

Examine your own setup and find the “weak link".  Remember, it’s not good enough to have the motor secured to the dinghy.  You have to secure the dinghy to the mother ship as well.  Get serious.  My 15-HP Yamaha costs $2000, and the average inflatable costs $3000.  Spend some time on this, and spend some money on good cable, chain, and padlocks.

Take care, and I hope to see you on the Rio.

Casey