Selection of carabiners

Two of our most recent short films for Adventure Kayak Magazine were on Contact Towing, and How to Make a Contact Tow Line. These two films generated quite a conversation with a lot of suggestions and comments, which is  what we want to happen.

There were some great alternative ideas for contact tow lines suggested, but the one component that we would change on many of them is their choice of carabiner. There are many elements of a tow system that can make or break a good design, and we think the carabiner or hook used to attach your line to the other boat is a crucial one. We have not yet discovered the perfect carabiner. This post is about our search for that perfect carabiner, what we know are the problems with some carabiners we have used over the years and what we hope someone will create in the near future.

Good Qualities in a Tow System

  1. It's quick to hook up
  2. It's quick to deploy
  3. It's quick to unhook
  4. It's quick to re-stow and make ready for use again
  5. You can release the system while under tension from yourself if necessary

The word "quick" comes up a lot in the list because often a tow is needed in an emergency situation, and a life may be at stake. As you design your tow system, you want to set yourself up for the greatest chance of success and anything that slows you down in setting up or getting out of a tow lowers your chance of success.

Success Spectrum

* And for the primary tow systems - the whole system must float! We are adding this one because of an unfortunate new trend we are noticing - tow belts without flotation.

Illustration by Leon Somme

The tidal waters in our area, which are often around 5 knots and can exceed 13 knots, a carabiner that sinks and gets caught on the bottom has a potential to pull you under. No river kayaker will ever think of having free end of the line sinkable.

The Anatomy of a Carabiner

Carabiner anatomy


This is our list of specifications for a safe and effective carabiner for safety and rescue:

  1. Must not corrode in salt water.
  2. Requires little maintenance.
  3. The gate fully locks to the nose in a key-lock. The gate therefore can't twist off the line when under tension. This also creates a smooth basket preventing premature releases from twisting.
  4. No notch or hook on the nose. Notches and hooks easily snag on deck lines slowing a rescue down. A carabiner hooked in a line in rough water often requires you to use both hands to unhook it leaving you with no hands on your paddle! A line in the hook under tension has the potential to weaken or break the carabiner.
  5. The gate has a large opening. The gate when held open, even with a gloved hand, must still have enough room to allow you to get it on and off the deck lines quickly.
  6. Fixed eye - rope is held in a separate hole from the main gate area so you never loose your line when you open the gate, or have it move to an unsafe position on the carabiner.
  7. You can carry the carabiner by the basket on your thumb. This allows you to hold both your paddle and the carabiner as you paddle in ready for a tow.

In a Search of Effortless Perfection

Utilizing the above specifications list we can look at examples of "High Success" carabiners and "Low Success" carabiners and the reasons they are on one side of the spectrum or the other. The goal is to find a carabiner of effortless perfection!

Aluminum Carabiners

Aluminum carabiners and mixed metal carabiners will corrode and eventually the gate will fail to open or close after a period of time (as the carabiner on the left shows, the gate is frozen in place by corrosion). They require lots of maintenance to keep them in working condition, especially in salt water environments. They are light and cheap so the are tempting to use.

We put these on the low end of the spectrum for violating the first two tenants of or specifications list: Must not corrode in salt water, and requires little maintenance.

Carabiners with Hooks on the Nose

Carabiner with hook - openCarabiner with hook with line

Carabiners with hooks on the nose easily snag on deck lines slowing a rescue down. A carabiner hooked in a line in rough water often requires you to use both hands to unhook it leaving you with no hands on your paddle! A line in the hook under tension has the potential to weaken, bend or break the carabiner.

Many paddlers will file the hook off the nose. This makes the carabiner unusable for taking on strong loads and can lead to the gate twisting off to the side and has the potential to weaken, bend, or break the carabiner.

Carabiners without hooks Carabiner with filed off hook broken

Above on the left is an image of a green carabiner with the notch filed down so it wont snag on the deck lines. The blue carabiner next to it has a similar nose, gate and method of operation but note the blue carabiner designed this way says "Not for Climbing". Right image shows the green carabiner with the hook filed off after a load was put on it.

Carabiners with hooks on the nose get a low rating for potentially slowing down an otherwise faster opportunity. Filing off the hook has the potential for the system to fail.

Carabiners without a Fixed or Captive Eye

In the above picture the carabiner on the left has a fixed eye to hold the line in place and keep it from sliding to the basket end of the carabiner and possibly to the gate and nose. The other three carabiners in the picture do not have a fixed eye. They do have some sort of line holder so its less likely for the line to slide, but over the years we have seen many carabiners, unknowingly absent their line, be hooked to a deck line in anticipation of a towing someone to safety, with the tower paddling away pulling only their empty tow rope.

One swirl around the vortex of a powerful whirlpool can cause what seems like a solid line holder to be moved with ease.

Carabiners without a captive eye get a low rating for the number of times we have seen unintended separation of the line from the carabiner. The line moved out of position also has the potential to damage to carabiner.

Plastic Carabiners

So far we have not found a plastic carabiner that works in dynamic water conditions. Some may be ok for recreational boaters staying in the intended waters of their craft, but the sea is not that place.

The side image shows the gate easily twisted off the deck line if it gets pulled to the side, which often happens in a rough sea.

Plastic Carabiners get a low rating as they all tend to fail in dynamic water conditions. This is too bad because they float, and we could remove the float from our tow systems if we could find one that works.

Wire Gate Carabiners

Wire gate carabiners have a tendency to snag on things and often the gate pulls apart making them useless. We give them a low rating for corrosion and snagging. And often wire carabiners have hooks as well.

Brass Carabiners

Brass carabiners resists corrosion, are maintenance free, and the one below has a captive eye. It meets almost all of the specifications in our list for a good towing carabiner.

However it does not have a key lock gate, it is too small to carry on your thumb, and its impossible not to block the opening with your fingers when putting it on or taking it off of deck lines.

We give it a low rating because it does not have a key lock gate and it is too small.

North Water Stainless Steel Fixed Eye Carabiners

The North Water Fixed Eye Stainless Steel Carabiner is the carabiner of choice for our primary tow systems. It meets all of our demands for a fast and effective carabiner for every situation we have found or put ourselves in. They resist corrosion and require almost no maintenance.

As shown above, North Water carabiner has a large basket for carrying on your thumb and a wide opening for getting it on and off the deck lines fast even with gloved hands.

There are no hooks on the gate. The gate and nose join in a key lock method producing a smooth basket and preventing premature releasing.

The only problem with this carabiners is they are heavy and require a float.

We rate this on the high side as it meets all the specifications of a well designed carabiner for safety and rescue.

Kokatat Genius SS Carabiners

The Kokatat Genius SS Carabiner is smaller and more compact than the North Water carabiner, and is the preferred carabiner for our contact tow lines, however some paddlers use it for there primary tow systems.

What makes the Genius Carabiner viable for a tow system despite it's small size is a gate that opens (kicks) off to one side. The advantage of this feature is that it allows you to hold open the gate with your thumb (even gloved) without blocking the opening. This allows you to get the carabiner on and off the deck lines quickly. It still has all the important safety specifications that are important to us for fast effective rescues.

We rate this carabiner on the high side as it meets all the specifications of a well designed carabiner for safety and rescue.

For other carabiners not being used in your towing systems, it is a good idea to have a locking gate to avoid accidental hooking on thing you don't want to be hooked to.

Working Towards The Perfect Carabiner

I've been experimenting with this carabiner and love its design. The thin metal gate performs like a key lock system while still being very light. it is however a mixed metal carabiner so it will corrode over time, and it still needs a small float. It also lacks a fixed eye.

We had high hopes for the plastic carabiner shown below on the right. It has a key lock gate, the basket is strong, there is an attachment to create a fixed eye, but the gate hinge is too weak for it to be useful in a towing situation.


If someone could combine the above carabiner with this plastic carabiner it would meet all the specifications on our list and would float, so we could get rid of the float on our line. We would have a nearly perfect carabiner for sea kayak towing systems.


Posted 14 June 2018 at 07:29 by Luc Le Blanc

Are you sure the spring inside the gate of stainless steel biners is also made of stainless steel and will never corrode? I would tend to trust better marine-grade fireman-style biners with a wire gate, thus spring-less and wholly made of stainless steel, such as this one:

Posted 21 September 2017 at 06:21 by Joie Gahum

Just like my roadeavour! Great stuff!!!

Posted 21 September 2017 at 06:21 by Joie Gahum

Just like my roadeavour! Great stuff!!!

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Posted 15 September 2016 at 18:13 by Michael Glavin

Note I have designed, built and sold outdoor gear for various companies for over 20 years, including carabiners back in the day (MSR and REI brand). The stainless biners you show certainly meet your requirements best, though the basket is small and they are heavy. Not sure what your issue is with mixed metal, since that does not necessarily equal corrosion. Aluminum is the issue: it will corrode in salt water. Anodizing helps, until it wears off (as when worn by a stainless steel gate; aka, mixed metal. The solution may be hard anodizing (like GSI cookware, and now others), This does not wear like standard anodization, and is as hard as garnet. There are many snag free wire gates available, like the final one in your analysis. These would require a much smaller float. I also like having a paddle sized biner on deck for quicky clipping off a paddle, as I am not a fan of leashes. Steel is WAY too heavy for this application, but as you show the biner is susceptible to corrosion, so they wear out too fast and can seize at the worst possible time. I keep it tethered to a 10 foot peice of webbing for use in rafted tow to allow the assistant to be able to release the system, and keep the rafted boats parallel. Steel biners are WAY too heavy, though, for this application. Hard anodization may be the key here, too.

Posted 04 October 2015 at 18:07 by Charlie Michel

I do prefer to hog ring my carabiner in place, rather than tie a knot.

Posted 18 August 2015 at 21:26 by Sanders

Extremely valuable information. I found it just in time as I am currently researching tow belts, their features and their hardware.

Posted 01 July 2015 at 13:36 by Dan

LOTS of very good information, and rationale for why one product is good/not so good. I think it will inspire readers to re-assess their tow rigs – even if they don’t change anything.

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