Wednesday, May 29, 2024
HomeScuba DivingReview: Fourth Element 2018 Thermocline

Review: Fourth Element 2018 Thermocline

When you live in the Bahamas and complain about the water being cold, no one ever feels sorry for you. Eye rolls and sarcasm are the standard issue responses I get when expressing the need for a 5mm or 7mm suit. While we are not shoveling snow, the water does get cooler in the winter and for me, this means a thicker/warmer suit.

The technology of wetsuits is advancing each year and thicker suits no longer mean sacrificing your range of motion. This is critical for someone like me, who always has a camera in hand. I have a freediving suit I love, but was looking to add another layer; enter the brand new Fourth Element’s Thermocline range.

This is an updated version of the original Thermocline lightweight thermal protection, which was designed as an alternative to wearing a wetsuit in warmer waters or to provide additional protection under your normal wetsuit.  The redesign comes with a much slimmer fit (the original felt a bit like a medium sized fleece) and a modern design that makes you look like you’ve in some Sci-Fi TV show.

Fourth Element 2018 Thermocline
Fourth Element 2018 Thermocline

It comes in a full range of options – from a traditional one-piece suit, through to a long-sleeved top and leggings, shorts and vest, a hooded vest, and two different swimsuits. Accessories include two different hoods (one with a skirt), and long and short socks.  For this review, I have tested the one piece, vest, leggings and long sleeve swimsuit.

I wore the vest and leggings under my freediving suit and they were very comfortable. I was concerned they might not fit right or make the suit tight, but they were pretty much unnoticeable. It’s also really nice to not have to add extra weight, as they are neutrally buoyant. This is especially nice if you are already wearing 5-7mm of neoprene. I tested the one piece under my Fourth Element 3mm suit and again was pleased with the comfort. Often times layering up leaves you feeling restricted and this was not the case at all. It took my 3mm to the next level of warmth with comfort and ease.

Fourth Element Thermocline Spring Suit
Fourth Element Thermocline Spring Suit

Finally, I braved the “frigid” water in just the just the one piece to see how it would perform. I do believe there is something magical in this gear, as it’s thin, comfortable and very warm. I wouldn’t do a winter dive in the one piece, but I believe it is on par with a 3mm suit, despite being only the equivalent of a 2mm. All the suits fit nicely under my other suits, with no bunching or the, “I can’t breath or move” feeling. I look forward to using them solo as the water warms up and I only need a lightweight suit.

We did have a fellow writer try out the suit in colder climates as a pool suit, the one downside they found is in colder air the suit wicks (i.e. water evaporates) very quickly and causes a real cooling sensation which is fine in warmer temperatures but in colder climates this might want to think twice if hoping to use this by itself.  We had to mark down performance because of this, although in warm water and air temperatures only it receives nearly full marks.

I am fairly tall, so getting suits long enough in the legs is always a challenge. These suits were just right and the sizing charts make it very easy to select your ideal fit.

Along with great fit and comfort, these suits are part of their Ocean Positive line.  Ocean Positive is Fourth Element’s range that utilizes ECONYL recycled nylon from ‘ghost’ fishing nets.  In fact, 78% of the outer layer is recycled nylon and other post-consumer waste so not only do you look good and keep warm but you are helping the oceans.

Selecting more sustainable products is something we can all do to make a difference for our oceans! And to round it all out, you can chuck them in the wash! Yes, machine washable for those who pee in their suits and those that lie about it!

One final note about price.  These are more expensive than similar types of product on the market, however I think the are good value for money.  The quality of the product, combined with the design and eco-material means they are well worth the investment.

Jillian in her Fourth Element Thermocline
Jillian in her Fourth Element Thermocline

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Key Features

  • Machine washable
  • Made from recycled materials (78% recycled Nylon)
  • Lightweight & breathable
  • Easy sizing chart
  • Various style options for men and women
  • Equivalent to 2mm wetsuit
  • Neoprene-free
  • Neutrally buoyant


  • Spring Suit – Men’s £219.95 GBP / $329.90 USD, Women’s £199.95 GBP / $299.90 USD
  • One Piece – Men’s & Women’s £249.95 GBP / $374.90 USD
  • Two Piece – Long Sleeved £239.90 GBP / $359.80 USD, Short Sleeved £209.90 GBP / $314.80 USD

BUY NOW – Fourth Element Authorized Dealer

Jillian Morris Brake
Jillian Morris Brake
Jillian Morris ("Shark Girl") is a marine biologist, shark conservationist, professional videographer/photographer, educator, writer and is absolutely obsessed with sharks. She grew up on the water in Maine and has wrapped her life around the ocean. She is the founder and president of Sharks4Kids, a shark education nonprofit inspiring the next generation of shark advocates through education, outreach, and adventure.


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I love this range of suits. They have a very Bond feel to them, you look good with a great design and fit, and if traveling can roll up into almost nothing in your luggage. Performance wise this range is definitely designed for warmer water and air temperatures though.Review: Fourth Element 2018 Thermocline