O three heated under vest

I bought this HUV after a particularly cold dive out of Eyemouth in 2012 when it was horrendous and after a good few dives I think I can say it remains one of my better purchases.

So what do you get for your hard earned cash, all £575 of it?


A ‘uni-size’ vest;

A custom divers battery (60-70 minutes run-time!) with charger;

A replacement drysuit inflate button; and

A carry bag:

This equates to a system that will keep you warm, please note that, through trial and error I found that it will not heat you up but will maintain your core temperature, if you go in chilled you will remain chilled throughout the dive, if you go in warm you will end you dive warm.

Fitting it to your suit is an easy operation but you must remember that the inflate nipple doesn’t move or swivel, it’s in a fixed position so make sure that you position it correctly otherwise you will have issues. The leads are nice and long so you have options regards where you store the battery, I keep mine clamped to the cylinder on a small pony clamp when OC diving and in a pocket of my ‘box when CC diving, oh the battery is a small aluminium housed pie and its fitted with ‘wet connections’ so swapping batteries underwater is not an issue.

The other issue to remember is that any layers worn on-top of the suit will need a hole cutting through to allow the cable to be run out to the inflate valve, easy if you wear ‘arctics’ or similar but not so easy in a romper suit, just a thought and something to do before you get ready to zip up!

Failures, well after a year of service the inflator button stopped ‘inflating’, now vac packed diver can very pleasing on the eye especially when you have an Adonis like figure, unfortunately I wasn’t because I haven’t! But O’three were excellent and provided a replacement FOC and with apologies, great service! Oh and a buddy had an issue on her system where one of the cables worked loose at the junction with the connector inside her dry-suit, a quick blob of aquasure resolved this issue, but a pain nevertheless.

Faults, a find it a bit tight around the neck and it does have a tendency to ride up, even with the crotch strap in place so it can be a wee bit uncomfortable, that said if you read my last sentence and do the math, 2+2, then this may not be a problem for the less amply proportioned diver…..

So, what options are out there for HUV’s and why did I pick this one………the first HUV that I saw is owned by a female dive friend who really feels the cold, she bought this vest, plus a spare battery and her UK diving was transformed and she is no longer a shivering wreck between dives and second dives are now enjoyed rather than endured!

A second friend has a hybrid of a typhoon battery and O’three vest, he didn’t care for the typhoon vest but as the typhoon system works on a higher voltage fitting the typhoon battery gives the O’three vest a higher heat output, so rather than simply maintaining your temperature his system has the oomph to ‘heat you up’. A good option but expensive unless you can organise batteries as spares.

If your UK diving is limited to South Coast dives of short duration then I would say that this is a luxury, likewise if your UK diving is limited to May through to October then perhaps you would find a better home for your cash. However  if you dive the North Sea in early spring you should seriously consider one, my last dive was in water at 5degC and it was chilly even with the vest, for the guys diving sans heater the dive time was very, very short on the second dive. 

Richies Ratings

8/10 for all year or long duration divers; and

5/10 for fair weather divers where it would be an affectation.

Recommended suppliers

Latest Photographs