Those of us who don't dive all that often may be tempted to skip the recommended annual maintenance on their regulators, or to only have it performed every two or three years. After all, if the gear has only been used on five or six dives in the last 12 months, it must not have been subjected to very much wear and tear. Right?
Actually, nothing could be farther from the truth.
Even for regulators and BCD's that only see occasional use, the recommendation for annual preventive maintenance still holds true. Actual use isn't the only thing that can create wear and tear on a set of regulators. Many divers have a tendency to store their gear under less-than-optimum conditions, and this in itself can create problems. If scuba gear is stored in the garage, for example, it is potentially subjected to dust, dirt, extremes of heat and cold, changes in humidity, and emissions from your car. Even equipment stored inside can be subjected to dusty or otherwise potentially harmful conditions. All of these things can take a toll on your gear, and especially on precision life-support equipment with lots of small rubber parts - like a set of regulators.
Will any of these factors cause a sudden, catastrophic failure of your equipment? Not likely. But they may cause minor problems which can interfere with pleasurable diving, or which can lead to bigger problems, or which may be difficult to take care of in the field when your buddy calls you and you suddenly find yourself on a plane to some exotic destination - without a chance to have the local repair tech go over your gear first. Even the cumulative effects of wear caused by making a few dives a year over several years, without any preventive maintenance being performed, can cause failures or substandard performance. Sure, we all carry a save-a-dive kit with O-rings and stuff in it...but wouldn't you rather be diving than fixing your gear on the surface?
Don't forget about BCD's and dive computers, too. Computers run on batteries, and as part of annual maintenance, the repair tech will check those batteries and replace them if they're getting low. And BCD's should be checked periodically to make sure none of the rubber parts on them have degraded or been damaged.
The bottom line? There's a good reason why we recommend that your scuba gear be serviced by a factory-trained repair technician every 12 months, whether it's being used a lot or only occasionally. Don't let skimping on something this simple ruin a dive for you somewhere down the line.