Way back in 2013 Mark Mulrain kindly sent one of the new IR K2 Union Suits to try out along with the Royale spraydeck. As I get ready for some cold weather paddling tomorrow it is still the thermal I go to first if I am planning on wearing a drysuit.

Immersion Research K2 Union Suit - Review
Immersion Research K2 Union Suit – Review

The K2 Union suit is till part of the Immersion Research range. This is what I said about the K2 Union suit a few years back.

Here is what Immersion Research say about the K2:

For many paddlers, the IR Thick Skin Union suit is the perfect paddling layer except for one small problem- in some cases, it’s simply too warm. The answer? The K2 Union suit. IR’s K2 fabric is a light weight Malden Mills Polartec® grid fleece (about the same weight as a cotton t-shirt) but it’s still remarkably insulating and dries lightening fast. Like the original Union Suit, the neck and shoulders are made with a super stretch neoprene that allow you to climb into the suit via the neck hole- no zippers necessary. This suit is perfect for shoulder season paddling or summertime on cold water rivers. It can be worn under a drysuit, or even matched with a dry top and paddling pants or shorts. If you’ve never owned an IR Union Suit before, get ready to fall in love with one piece layering, and if the IR Thick Skin Union suit is already your favorite piece of gear, this is the perfect companion.

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The Union suit is a one piece thermal suit that has no zips, poppers or any other fastenings to worry about. This reduces the chances of discomfort and will prevent any drafts or bare bits of flesh. This is often an issue with two piece systems.


This version is a limited run. It’s thicker than the final version will be and is a bit of a custom order that Mark has persuaded IR to bring to Europe.


Given the material used you get something a little warmer than the standard K2 but also at a cheaper price. Which can’t be a bad thing.

I’ve had the K2 for a few months but have only just started to use it as the weather has now started to get colder. I initially thought that it would be a struggle getting into suit through the neck. On first glance it doesn’t look big enough or stretchy enough to squeeze through. But it is.

I found the K2 to be spot on. It wicks well and has a good balance of warmth vs bulk. It is super comfy to wear and if it does get wet dries quickly. Taking the suit off is a bit of an art. It takes a little bit of practice before you can do it elegantly but it doesn’t take long to get a hold of.

UPDATE October 2021:

I expected that as the neck of the suit is used to put on the suit that over time this would become baggy but this hasn’t been the case.

If it is super cold I do add another thin merino thermal top underneath the Union suit just to aid it a little.

Having been worn several hundred times the suit is still performing well and I haven’t had any issues with it wearing out or falling apart.

You can get the newer version here which runs at £89. They also have a thicker Union suit at £79.