Thermalux Undersuit


Thermalux undersuits offer a lightweight, streamlined solution to keeping warm.

The hi-tech fleece and Lycra® mix gives superb insulation and flexibility and is completed with a breathable microfibre outer. The materials used mean the suit is quick-drying too.

Super flexible, warmth-retaining panels are present in the lower back, shoulders, cuffs, lower legs and feet.

Ergonomically designed foot stirrups keep you comfortable when diving.

This undersuit has a tog rating of 2.3.


  • Breathable microfibre outer shell
  • Super absorbent micro fleece inner lining
  • Bacteria and fungus resistant
  • Lycra® panels
  • Thermalskin cuffs
  • Thermalskin foot stirrups
  • Hip pockets
  • Two -way zip
  • Tog rating 2.3

Delivery, Returns & Instore Collection

When will I receive my order?

International Delivery Times

Monday – Friday 3 – 5 Working Days

UK Mainland Delivery Times

Monday – Friday before 2pm Next Working Day
Monday – Friday after 2pm 2 Working Days
Saturday & Sunday 2 Working Days

UK Extended Areas Delivery Times

Monday – Sunday 3 – 5 Working Days

Please note delivery times may be extended during busy periods.

EU Areas

Please note that due to changes by HMRC, orders being shipped to EU countries will not be shipped on the same day as they are invoiced. EU Orders will now be shipped on the next working day. This only applies to E.U. orders. Domestic and Worldwide shipments remain the same.

Collect In Store?

When you go to the online checkout, you can opt to collect your items in store. We'll let you know when your order is ready for you to collect. Your order will normally be ready to collect the next working day.

Returns, refunds or exchanges?

You can return any item within 28 days of receipt for a refund, provided the item is unused, in its original packaging and in 'as new' condition.

Items will be refunded in full (less postage) if received within 28 days from the date of despatch.


We aim to deal with all returns and exchanges on the day they arrive, however please allow longer during peak periods.

You can return the item(s) by dropping them off in store or by returning the item(s) by post. We do not insist on a specific courier service for the return, so please use the most economical or appropriate method for returning the item(s).

Northern Diver (Int) Ltd
Appley Lane North
Appley Bridge

If an item becomes faulty after a period of time then please contact customer services (01257 254 444 or prior to returning the item. We will either repair or replace the item at our discretion.

Tell Us What You Think

Customer Reviews

5 out of 5 Stars (6 reviews)

Write a Review

A fantastic undersuit

By Phil Holt on 05 Feb. 2016

Have shopped with Northern Diver before and their service is second to none. Discussed with Lee the best undersuit for my needs and requirements at about 4:30pm and the suit arrived the very next afternoon! Very pleased with it - great design and very comfortable. Thanks!

Awesome Suit and Awesome Service - Delighted

By Rob Turner (South Bay Scuba - Scarborough) on 03 Jun. 2015

First time I've shopped at Northern Diver. Rang to get some application and size advice on an under suit (to replace my Weezle) and a hood. Janis dealt with my call and from the outset I was impressed by the level of customer service. Took a real interest and nothing seemed to much. Bought over the phone late in the day. Next day delivery, well packaged, awesome, suit, awesome hood and both a perfect fit. Really impressed with the design of the Thermalux. Well thought out stretch panels, nice tapered fit to the lower legs and great foot fittings. In my view knocks spots off a Weezle and at half the price. Also, I had a small post-sale customer service issue and they simply jumped all over it. One delighted customer here. Happy to tell the tale far and wide and will definitely be back. Well done guys!!!

What a pity it didn't fit..

By Cathy on 28 Sep. 2013

This is a really great undersuit, I really wish it had fitted me, but sadly I seem to fall between sizes, so will have to look for something else. However, thanks a million to AL (Northern Diver) who went way beyond the call of duty trying to help me. I am so impressed with the service from Northern Diver, I will not hesitate to recommend them at every opportunity.

Extremely Warm and Useful Undersuit

By Scott Davis on 18 May. 2013

What a great undersuit, thanks Northern Diver. I have a Metalux Temperate and don’t get me wrong, it’s great but it’s a bit too great (too warm) under my Neoprene drysuit. Ok for water less than about 6 degrees and for the rest of the diving I do, I was simply using a pair of tracksuit bottoms and a thick T Shirt. This worked ok but didn’t look professional and as my drysuit is quite a tight fit after the Christmas ‘drysuit shrinking’ period, it was also a bit uncomfortable at times. Tried Northern Divers Thermalux undersuit at the Birmingham NEC Dive Show last year and instantly loved it. After almost a year of use, I can say that it’s a bit more thermal than my ‘low tec’ under garments and not as super warm as the Metalux, with the added ‘one piece’ bonus to keep it comfortable. Now I have the perfect undersuit combination and I also find that adding a thin base layer to this Thermalux, bridges the gap between summer and winter diving. Thanks guys, look forward to seeing you again at the NEC dive show in just over a month.

Snug and Safe

By David O'Mahony on 05 Nov. 2012

Derrynane Inshore Rescue unit bought these under suits for our crew and they rave about them. Aside from the crews' reactions I, as Secretary, found Northern Diver a breeze to deal with, great service and price, terrific delivery times and sizing. We are exceptionally pleased with the Thermalux undersuit and have no hesitation in recommending N.Diver and this suit to any diver or SAR unit.

A fantastic undersuit

By Phil Holt on 04 Aug. 2016

Have shopped with Northern Diver before and their service is second to none. Discussed with Lee the best undersuit for my needs and requirements at about 4:30pm and the suit arrived the very next afternoon! Very pleased with it - great design and very comfortable. Thanks!


Trade Customers

Northern Diver offers trade accounts to commercial organisations and to those who work in or around water. Please click here to register your details and find out if you qualify. Once your trade account has been confirmed you can view all trade prices and shop easily online when logged into your account. Please note when you are not logged in to your trade account retail prices are shown. If you have any queries please do not hesitate to contact us. Tel: +44 (0) 1257 25 44 44.