This is the ‘Big Daddy’ of lockers – the ultimate rigging biner and one which is super strong and super tough. This makes them ideal for kayaking. I’ve had a number of Boa carabiners in my gear inventory for the last four years.

DMM Boa - Review
DMM Boa – Screwgate (Left) and Locksafe (Right)

The Boa is large enough to accommodate several knots and has a very wide gate opening. The two main types of Boa I have owned have different locking systems. The one on the left has the traditional screw gate and the one on the right has a lock safe gate system. The photo above makes it look like the two carabiners are of different sizes. This is not the case. They have the same dimensions.

DMM Boa - Review
DMM Boa on a Palm Rescue Tape

After four years of use I still use the screw gate type but have moved the lock safe version on. I personally didn’t like the way in which the system unlocked. It functioned well but I didn’t get on with it at all as I found it a fiddle to open one handed.

DMM Boa - Review

This may be due to the fact that after years of climbing I am more comfortable with the screw gate locking system. I suppose I also like the idea of deciding when I want or don’t want to lock the gate. The screw gate allows it to be my choice.


Large clean nose HMS locking biner
Ideal for rigging; can accommodate multiple knots
Large gate opening
Easy to handle in gloves
Strong I-Beam construction to save weight (almost 25% reduction)
Available with Screwgate, Quicklock and Locksafe locking systems
Available in colour packs for easy identification

Weight wise all of the range sit between 80 and 90g so not a huge weight penalty for such a large HMS carabiner.

DMM gear does seem to stand the test of time. I have used DMM carabiners for climbing and boating duties without issue.

Here’s a shot of a Boa that has had some heavy use having spent its time in a sea loch on the North West of Scotland for over a year.

DMM Boa - Review

I now have quite a few of these including some of a different colour. Red, Green and Blue are available in a multipack. If setting up a complex rigging system is is good to be able to identify different bits of gear by colour rather than just be position.

DMM Boa - Review

So other than the DMM Boa the only other locking carabiner I carry on a regular basis is the Petzl Vertigo wire lock. This has an auto locking function but is super easy to use one handed even if wearing gloves.