Apeks -- flimsy pieces of nonsense. The manifolds warp as soon as you look at them and it is just about impossible to get the cross-over nuts to tighten securely, and to stay tight for more than one dive. How this thing survived a 300bar fill is beyond me.

Their single valves are atrociously designed too. The outlet is far too close to the top of the cylinder, attaching a regulator is awkward to say the least. On stage bottles they are horrendous. The knobs also seem to accumulate salt and other deposits faster than other valves making them very hard to work.

Anything 300bar. A 10litre/300bar bottle may hold more gas than a 12litre/232bar but that assumes that you get a 300bar fill. Few places do good 300bar fills, forget it with field compressors. Mixed-gas, especially trimix, at that pressure is a nightmare for the poor sod doing the blending.

Do not even consider 7litre/300bar for deco stages, they are far too heavy.

Anything steel. The buoyancy characteristics are very poor. It means you need a bigger wing, which means more drag, which means a double wing in case it fails, etc.If you ever need to take a deco bottle off then you are going to rocket to the surface as soon as you let go. If you use one then you need to chest mount it or you get pulled off side. Been there, learned from my mistakes. Buy aluminium.

Any jacket type. Why would you want everything flopping around when you can have it tight and streamlined? Madness.

Bungee wings. Any leak or dump valve failure and they will deflate in seconds, and will not hold air. Oral inflation underwater is just about impossible. Bungee is crying out to get trapped, and the elastic stuff is the worst. Why do you need such a big wing? Mostly to offset the negative buoyancy of steel stages, which can be offset by using aluimium instead. OMS and Dive Rite are the worst offenders. Custom Divers though far exceed their levels of crapiness.

Double wings. Why do you need two wings? Again, if you use the right cylinders and backplate then you should float with your suit.

Dive Rite ABS plastic backplates. They usually crack just off-centre, where the plate bends. This is a pivot point, metal will bend, plastic just breaks.

Fancy harnesses. Fastex clips will break, I have had it happen, usually when you attach a stage on the surface. On Dive Rites, if the female clip breaks then you need to replace the whole harness as it is stitched in place. The shoulder clips pop when you reach across your body, like when using a shoulder dump valve. Chest straps are unnecessary. It is hard to get the d-rings in the right places. Adjusting the harness is a nightmare too, you can never get it right.

Harnesses which cross behind the neck. Why? What is the point? They just reduce your range of movement.

Again, the usual suspects are Dive Rite, OMS and Custom Divers. Total rubbish.

Industrial webbing. Too smooth and shiny. Very strong but d-rings just slide all over the place when you load them.

Poseidon Jetstreams/Odins. It takes a special breathing pattern to get the best from them. Will you be able to maintain that pattern when you are under stress? What is usually the first thing to go? What happens if you pass it to a panicked, out of air diver? They also freeflow at the drop of a hat. Have a good credit rating if you want to get them serviced properly, that is if you can find someone who will do it properly. The overpressure valve on the first-stage will start to leak eventually, and the weird fittings on the second stage means you can only use expensive Poseidon replacement hoses.

Force Fins. Ludicrously expensive and impossible to use without creating a dust storm behind.

Mares Quattros or anything that costs a small fortune. Why? They are just lumps of plastic. Get a life, if you want to go fast then buy a scooter.

Pistol grip lights. They take up the use of one hand, are bulky and the light isn't that good. They eat batteries and NICAD rechargeables take forever to charge for not that long a burn, then they die without warning. For what a UK800R costs you could get a Meteor 4 umbilical.

Custom Divers cannister lights. Flimsy and poorly made. Plastic lid on a steel cannister, the materials expand at different rates, making removing the lid hard at best, causing leaks at worse. They have a twist reed switch which is very fragile and expensive to replace, it also puts a strain on the cord. Broken wires are very common. The light heads use a capsule light unit instead of a test-tube type. You cannot focus the beam, and as they are intended for display spotlights, the light quality tends towards yellow rather than white. Expensive to replace and fragile. Dodgy connections and blown fuses are par for the course.

Niterider. Over-priced, impossible to replace any of the parts, even the bulbs. The bulk-head seals are a joke, take one apart and look at it if you can. Switches are unreliable. Very difficult to change the batteries in the ones which used disposables.

Ikelite C-Lights. Absolutely huge, difficult to stow anywhere.

UK SL4's. Weird shape, difficult to stow. Bulb is overpowered making it more likely to failure. Mechanical switches prone to failure at depth. Certain Niterider models use the same switch, I had one disconnect at 65m in St. Sauveur cave in France.

Anything with a switch. A potential leakage point, switches are difficult to find with cold hands/thick gloves and prone to failure at depth.

Clicky reels. Hard to use, huge and do not hold much line.

Custom Divers. The twist lock often locks up when sending a bag to the surface, taking either you or the reel with it. They use cheap clips, I lost two because of the clips alone. The plastic on the drums cracks and they are hard to take apart. The frames are flimsy and bent very easily whilst in use. How this company turns a profit without being sued is beyond me. Producers of the worst kind of rip-off rubbish.

All knives in general. They take two much effort to cut anything, forget it for netting or coils of monofibre. They rust, are hard to keep sharp and are expensive.

They look good, especially a great, big machete strapped to the ankle. Buy shears. You may look like a gardener instead of a SEAL but at least you can cut your way out of everything.

Northern Diver. The most uncooperative company in the diving industry. I could forgive them if they made good suits but they do not, they self-destruct after a few years and are not that well made to start with. Their 2mm neoprene suit is closer to 4mm and very stiff. The soft boots fall apart and the latex seals are cheap and nasty.

Typhoon Tracer and other lightweight drysuits. Does that extra 1kg of weight matter that much? For the same money, buy a suit that will stand up to more than a dive in a swimming pool. Complete rubbish, the manufacturers of such stuff should be ashamed and flogged through the streets to make up for it.

O'Three: see neoprene below. Overpriced and slow service. Sponsors dangerous stupidity like deep air record attempts.

Neoprene. Compresses at depth. Suddenly you lose all your buoyancy at depth and your thermal protection. Very easily damaged and you will bake on the surface. Often inflexible and uncomfortable

Compressed/crushed neoprene. Heavy, stiff, does not live up to the company spin. Leak finding is a nightmare as the outer surface soaks up the soap solution before it can bubble.

Back entry. Reduces your range of movement. If you get separated from your partner, how do you get to your car keys?

Useful if you want to develop your mental arithmetic skills by calculating your deco in your head, because that is what you need to do with one of these things. They switch themselves into error mode or off completely at every opportunity, the multi-gas models have no contingency features if you lose a deco gas, the back-light burns through batteries. I personally had two fail on consecutive 70m dives.

It acts like scissors, chomping away at the rubber hose sheath as it flexes. Traps salt and sand causing wear underneath that you only find out about when it blows.

Unreliable, freeflow too easily. Most people forget about servicing them. Buttons too easily confused. Not needed.

If you think you need a pony bottle then you need a twinset. If you think you do not need the pony then do not take it.

Just a hazard. I have never been stupid enough to buy them. How hard are you going to hit your valves. Maybe you should look at your buoyancy instead if you think it is a problem.

If you cannot reach your manifold then you should not be using it. What happens if it comes off? Another good idea gone wrong.

Great if you are a firefighter or a naval diver. For the average wrecker, just more crap peddled by rags like Diver magazine. Think it through, the hazards are obvious for technical/recreational diving.

Like valve protectors, if you think this will be a problem, sort out your buoyancy. Except when hitting dry cave during a dive, there is no point.

Manic Street Preachers. Before a dive they will put you in a suicidal frame of mind (not good) and post-dive they will instantly destroy your high. Avoid especially in the area of high bridges, the temptation to jump could well be too much.

Anything where the band members were born in the eighties.

Anything by the Fun Lovin' Criminals after Come Find Yourself.

Local commercial radio. Just don't! Don't! It's not worth it! There is nothing on local commercial radio other than weather and traffic reports that you would thank them for. Anyone who has had to suffer Tiger Tim Stevens or George Bowie on Radio Clyde knows what I mean.

Radio Two. A Radio Two DJ once apologised on air for having to play Primal Scream at two o'clock on a Tuesday afternoon, that says it all. Sarah Kennedy, do you really want to listen to a red-cheeked Zepellin talking bollox for two hours? Steve Wright, Ed Stewpot Stewart, David Hamilton and the madman who got done for using coke, noooo!!!! Even listening to the Manic Street Preachers beats this!

Radio Three. Way too far up its own arse, although do not write it off completely. Classic FM is far too mainstream, plus it has commercials.

Virgin Radio. Once had good DJ's who played some great music. Most of them left when Chris Evans took over. Sycophantic rubbish on the breakfast show, followed up by no-hopers and copyists (could Pete & Jeff be any more like Mark & Lard? -- yes, they could be funny but they are not), playing middle of the road, old rot. At least Radio Two is FM, this is crackly AM mono unless you live in London village. Oooh, musht gerrumble!

Renault Meganes. Poncey, middle class cars designed for smug middle managers and their wives. People who play tennis should drive these. Anyone who shows up at a dive site in a Megane should be pointed at, insulted and generally humiliated until they start to cry. Rattley, tiny boot, crap stereo, slow, even the 16V versions. Low ground clearance so expect serious underside damage if you use it anywhere other than city roads.

Suzuki Swifts. Tiny, noisy, slow. Half the engine is missing and lots of the bodywork is plastic which scratches easily and is hard to repaint and repair.

Clapped out Volvos. Windey, narrow roads and Volvos, no! They just do not mix, think of other people.

Mercedes, BMW, Audi or Lexus. You will inevitably find yourself buying every post-dive pint every single time, otherwise totally sound. Jaguars are the exception as they are just ultra-cool, but crap for diving.

Saab 90's. They have all the benefits of Cavaliers/Vectras (they share the same GM design) but are double the price and expensive to service. Plus everyone will think you are a social worker or Labour MP.