Beneath the Surface – The HALO A°R Undersuit

It’s finally here! The long-awaited and long-lusted for HALO A°R undersuit!

Fourth Element’s new undersuit has been the stuff of legend – or myth – since 2019, when we first showed it at the DEMA Dive Show in USA, and when the world was COVID free.

Alas, crises and global events put spanners in the works for this awesome suit – but the incredible team we have at fourth element battled on, overcame each hurdle and jumped through all the hoops to finally be able to get the HALO A°R to you!

So, what’s so groundbreaking about the HALO A°R undersuit?

Well, it’s the first drysuit undersuit in the dive industry to use Aerogel as an insulator. Aerogel is the most insulating material available and was developed for the space industry and cryogenics. It has in fact, been on fourth elements’ radar for almost two decades!

An undersuit 20 Years in the making

Jim and Paul, fourth element’s founders, have experimented with the material for nearly 18 years, but only recently has the development of the material reached the stage that it can now be used at pressure without disintegrating. At this point, it was immediately handed over to our design team to start the development of a new undersuit.

The brief for the design team was to create a suit to improve on our (previously) warmest undersuit – the Halo 3D.  What made the the Halo 3D so warm was strategically positioning spacer panels in areas that need most insulation for a diver in trim. The gas in the suit travelled to the highest point and all that warm air only insulated the back and behind of the diver in trim, so the chest and thighs needed additional insulation. This made the Halo 3D a fantastic suit, but quite buoyant and quite bulky.

Additionally, we also used Thermal Imaging to analyse where the biggest heat-loss was on the Halo 3D, and it was quickly very clear that the greatest loss was down the middle of the chest where the entry zip was.

With the innovative new insulator and these changes at the forefront, the new HALO A°R has the zip off-set to the left side – this is not just to look cool (which it does!) but to have a full 3mm Argon Aerogel panel covering and insulating the entire chest and your core organs.

There is also 3mm Argon Aerogel on the front of the thighs, but also on the back and on the behind of the HALO A°R (as shown on the graphic). As mentioned earlier, the gas in the drysuit travels to the back of the diver when in trim, but equipment squishes away the gas down onto the back and mostly straight onto the kidneys. As there is a lot of blood circulating the kidneys, we have insulated them fully with 3mm Argon Aerogel for your overall comfort and warmth. The 3mm panel on the backside is not designed to keep the you warm during the dive, but to keep your butt nice and warm both before and after your dives!

3mm Argon Aerogel has also been placed on the inside of the wrists of the HALO A°R, as the bloodflow to the hands runs close to the skin and this again helps keep your hands a littler warmer.

1mm Argon Aerogel panels have been placed where more flexibility is required, on the outer-arms and behind the knees – and finally high-density fleece, like we know and love from our Arctic undersuit, has been placed where both maximum flexibility and low-bulk is required – underarms to reach those valves for shutdown, and on the ankles where we need room for the Hotfoot Pros!

With the outer layer of the suit being windproof and water-resistant, it will keep you cosy when exposed to the elements, but the slick exterior-and the fact that the HALO A°R is a onesie – makes donning your drysuit over the HALO A°R a dream! You just slide right in.

Figuring out the most optimal way to route the p-valve hose – for both males and females – we feel we have come to a brilliant solution! There are two pre-stitched slits on the waist, either left or right, that you can cut open. Connecting the p-valve was also a challenge with the zip being off-centred and that has been solved by installing a second zip within the pocket, so that you can easily access and connect without using contortionist flexibility.

All of this gives you the warmest weight-for-weight undergarment we have ever made at fourth element – whilst still being extremely flexible and with very low bulk and very low buoyancy!

I have been diving my HALO A°R for over a year and I absolutely love it and am actually starting to almost dread the summer season when it will be too warm to use it!

I know – I am biased and I work at fourth element, so don’t just take my word for it – go try it for yourself and please let us know what you think! We love to hear feedback from you and it’s for you we design our products ?