Training is the first line of defence a diver has and yet everyone has horror stories of divers who are qualified and who, to all intents and purposes, cannot dive. Often they are unaware their diving practices are intrinsically unsafe - why should they be? After all, their C-card says they are qualified. There are two problems with diver training. Firstly, some instructors do not teach to an adequate standard. Secondly, some divers often don't bother with formal continuing education whilest moving into diving activities for which their level of training is insufficient.

The problem of irresponsible instructors is a tough one. Some training agencies do attempt to keep tabs on their instructors by asking students how their course was conducted. If the agency detects a problem they will investigate and possibly expel the offending instructor. However, there are lots of instructors to monitor, often in far-flung places and not all belonging to agencies anyway.

Divers who exceed their training limitations are not uncommon. For the most part they seem to get away with it, but that is more a matter of luck than judgement. The defensive diver strives to remove luck from the equation and in doing so also removes chance - chances are something you take with lottery stakes, not lives. Entry-level training is just that - it qualifies a diver to dive under quite restrictive conditions, that's inevitable. Especially since trainees need to be kept safe during their first dives which normally take place in warm, clear, calm conditions such as a pool or protected beach into the sea. Cold, turbid and rough water would make for a challenging and potentially dangerous contrast, so ideally these conditions are avoided. The end result is the trainee makes four or so dives under often unrealistically favourable conditions, before being turned loose. The environment they face after certification may be much more hostile and may lack an instructor or divemaster to ride shotgun and keep them out of trouble.

Some divers claim experience is the best teacher, not training - I doubt it. Experience can be a great teacher, I've learned a lot from other divers' fatal errors - for them, experience was a final lesson learned too late - no expense spared - I though, on the other hand, incorporate their experience into my training.

Merely learning to dive does not aquaint a diver with the multiplicity of diving conditions and pursuits they are going to encounter. Being a great diver who can handle currents and depth does not mean you can handle anything. Ideally, every diver should be trained up to the point where they can individually manage a rescue and be formally trained to undertake hazardous pursuits like deep diving or entering overheads (if this is where the interest lies). Some divers often dive independently of professional supervision and so must be able to avoid trouble, or at least cope with it independently. Even when professional leadership is on hand, it's best to have somem insight into what you are doing - even pros make errors of judgement. Perhaps I was exposed to a particularly careless set of instructors, but I learned early on I was safer trusting my own judgement rather than theirs, even as a rank beginner. Leadership divers, like customers, are empatically not always right - we're not scuba gods, just guys with badges who screw up in front of an audience! It's important to stay in practice. One advantage an instructor has is, they are constantly demonstrating skills, which keeps them sharp. Often divers complete a course never to repeat basic skills like alternate air source use again, except in an emergency. Some divers who only dive on holiday once or twice a year seem unwilling to invest additional time going through a skills review in a pool beforehand. Reviewing skills is an investment in your safety and by being proactive and preparing for diving you are less of a liability to your companions.

Like many people, my work keeps me out of the water more than I would wish. Before a trip I like to go and workout in a pool by doing a few skills and pitting myself against the Diamond Reef buoyancy clinic. It's no different to any sportsman keeping in shape in the gym before an event - it certainly helps me!

Keeping in touch with advances in diving is to be recommended. Magazines often carry articles explaining safer ways to dive which can contribute usefully to your diving knowledge. This is especially true of avoiding decompression illness, where research continues apace. An excellent publication is Alert Diver by Divers Alert Network, which should be considered compulsory for all defensive divers.

It's good practice to review your dive manuals once in a while and working through a few dive table questions or reviewing your computer instructions is usually time well spent - it's so easy to forget procedures after a layoff.

Above all, don't try to bluff other - or yourself - about your level of diving skills. Anyone can spot a poor diver instantly, often before they even hit the water. Behind the facade, most poorly skilled divers know their personal diving ability doesn't cut it. Fortunately, most divers can easily achieve a high standard of proficiency through a little extra coaching - asking for help sure beats public humiliation!

The message here is simple - stop training physically and mentally for diving and you don't stand still: you go backwards - rapidly. To be a good diver you must, at the very minimum, seek to maintain your skills and knowledge: over-learn, over-train, and don't get complacent - you are never that good.