When Diving Unlimited International (DUI) introduced their CF200X drysuit into the UK in 1989 it attracted immediate attention as it offered a range of benefits unavailable in any other single suit. It was also one of the most expensive drysuits ever sold in the UK. Despite the high price it quickly won acceptence. Six years on, the CF200X and its derivatives have been immensely successful among instructors, technical and wreck divers and others who make regular use of their suits under harsh conditions.

The CF200 series are membrane drysuits designed to keep the user dry, but provide minimal insulation themselves. Instead, undersuits are worn to suit the dive and diver. In a unique and patented process DUI take 4mm expanded foam neoprene, made by Rubatex, and assemble the suit body. Seams are stitched through the suit, rather than cup or strobel stitching, which leaves a watertight seam. The entire suit is then pressurised under water in a special chamber to crush the material to just 2mm. The process leaves the neoprene extremely supple, with excellent four-way stretch and also makes it incredibly resilient to abrasion and cuts.

The CF200X offers great versatility in sizing thanks to DUI's telescoping torso, braces and crotch strap. The length of the suits is greater than that of the wearer, the excess being folded under at the waist. Adjustable braces hold up the bottom section of the suit, while the adjustable crotch strap holds the top down. The suit remains close in until extra reach is needed and then the suit lengthens and recoils as the diver moves. It's an elegant design.

The 200X also has a front zip which keeps the diver independent, since help isn't needed to open or close the zipper as with back entry designs. Another comfort feature is a gusset round the neck seal that traps the bib from some DUI hoods. This helps to keep the diver's neck warm and stops the bib flapping about. The suits are normally supplied with bicep-mounted, adjustable automatic dumps and inflator valves by Si Tech or Apeks.

I have had my CF200X since 1990 and have made hundreds of dives in it. When I taught professionally I would spend all day in the suit. It proved very comfortable in and out of the water. Wind chill is a problem out of water as the wet nylon facing whisks heat away. On warm days, the suit top can be folded down. The braces stop it collapsing around your ankles and the arms tuck through them, which is very convenient. The front zip provides easy access to the inside pockets that are fitted to many undersuits.

The original valves were made by GSD. The inflator has been entirely reliable. It has never frozen, even at depth in near freezing conditions and requires virtually no finger pressure to operate. The exhaust valve was faulty when the suit was supplied. DUI replaced it with a Si Tech without quibble. The Si Tech is very effective, though bulky. It can catch on straps as you gear up, but has never snagged on anything in the water, even in closely confined wrecks. Through my own carelessness I have jammed it once, probably by not rinsing it properly. Nevertheless, I was able to vent air through my wrist seal.

The CF200 material has stood up very well. The kneepads are cosmetically scuffed, but otherwise undamaged, from kneeling on sharp quarry beds but the suit itself remains unpatched. I have replaced the wrist seals twice and the neck seal once. Both are neoprene and have stood the test of time well. The zip has been replaced once following improper storage. DUI have completed the repairs quickly, but once supplied an improperly sealed cuff.

I use a DUI Thinsulate undersuit with Ultimate thermals below it which for normal recreational dives throughout the year has been fine. Disadvantages are few. For me, the main problem is the weight involved if I am travelling. If the suit is still wet when you pack it then the problem is exacerbated. Ankle straps designed to keep your feet secure in the boots and reduce air migration, fell off several years apart and I don't miss them. The soles were re-attached after they started to delaminate from the uppers, but in fairness they had seen a lot of hard use. I would much prefer harder-soled boots. The soles are thin and one feels every pebble through them when shore diving. On decks they are fine. These are very small quibbles and it reflects very well on the CF200X that I own that, after so many years of abuse, the suit has survived at all. If it wears out I'll probably buy another one. Steve Warren