Once you have collected all your dive gear, it immediately becomes apparent that you need something in which to put it.
Alas, so many new divers purchase this important item as an afterthought. A bag might seem an uninteresting part of the kit, but the right one is essential to your diving happiness!
Strangely enough, a bag that is ideal for transporting the gear might not be entirely suitable for use on site. One that is so roomy that it takes every bit of kit you have to offer can become too heavy and unwieldy to handle once loaded.
It might even prove too weak to take its own weight. Two smaller bags might be more suitable.
An extra-large cargo pack might be strong enough to take both your diving equipment and that of your partner - but hopefully your partner is also going to carry it for you!
Airlines, increasingly aware of mounting health costs for their employees, are beginning to limit the weight of individual pieces of checked-in baggage. Those of us not yet suffering from bad backs might take a leaf out of their book!
One thing should be accepted - no dive bag offers security for the contents. A padlocked zip merely offers an early indication that the bag has been tampered with. No bag is immune from the determined thief armed with a knife.
On the subject of zips, avoid metal ones. Metal and saltwater are troublesome bedfellows. Never mind thieves, you could end up using your knife to fight your way into your own bag!
We last reviewed dive bags in 1991, when we counted 18 of them. Today we have identified more than 140 items that qualify for listing. There seems to be a bag to suit every diving purpose.
General dive-bag designs vary from duffel bags such as the Beaver Duffel, closed by drawstrings, and traditional sports bags or hold-alls (Poseidon Dive Bag and Dream Marine Standard), to more sophisticated rucksack-style bags and those that are so capacious they certainly need the wheels with which they come equipped.
The duffel and sports bags and hold-alls offer the sort of simplicity that might well be appreciated in the confines of a small boat. The larger bags would be most unwelcome in those circumstances but do have the ability to segregate wet items from dry, and your day clothes from your gauges.
Some, like the N-Diver Scubapack or the Cressi-sub Mobi, even include separate bags within the main one. However, they are probably more suitable for the broader job of transport rather than for delving into on a moment-to-moment basis.
Dive bags also vary greatly in price. The most expensive identified for sale in the UK is close to £250, while the cheapest that does a similar job is only about £30.
This variation is reflected not only in the design but also in the quality of construction and the materials used.
A cheaper bag might not take the heavy wear possible with a more expensive example - airport baggage-handlers are expert at exposing any weakness in a bag - but then there is no point in paying a lot for one that spends most of its life in a cupboard.
Either way, it is certainly worth examining how the handles are attached. Anything less than the most serious reinforcing will soon see the handles ripped away from the main material of the bag, thereby rendering it useless. You could even do that to your own bag just by lifting it awkwardly from the boot of your car.
Many bags such as the Scubapro Carry All and the Deep See Travelok 1500 come equipped with rucksack-style straps. These are often hidden away behind a zipped panel when not required, and provide a comfortable method of carrying heavy loads, especially over uneven ground.
Bags with wheels, such as the very expensive yet extremely durable Stahlsac XL Dive Cargo Pack, come into their own on the smooth surfaces found at airports. Be aware that any part of a bag's material that comes into contact with the ground when being rolled on wheels will be subject to wear, and will soon display a hole at the point of contact.
Further sets of bags have specialised applications. Regulator bags like that from Spiro are designed for those precious items a diver might prefer to carry separately, both when travelling and also at the dive location. Mesh bags like the IST Mesh Gear Bag are ideal for taking out in a boat.
The Sherwood Mesh Bag doubles as a handy seat-cushion once the contents have been removed.
Mesh bags allow the diver to dunk the whole thing with its contents in a tank of fresh water on returning from a dive. This is a good idea unless you want to place the bag immediately in the boot of your car afterwards!
Other bags are designed to keep the water out and are for keeping day clothes and drysuit undergarments away from the wetness invariably encountered in the boat. The OMS Truly Dry Bag is a good example of this style but it must be said that it is probably not so suitable for checking in as aircraft-hold luggage.
Finally there are numerous examples of smaller bags designed for very specific uses. Fin bags, mask bags, goody bags, bum bags, tool pouches and pony pouches - their type-names are self explanatory as well as intriguing. There seems to be a bag to fit whatever specialised item you might have to put in it.
Any bag used for diving equipment will come into contact with seawater at some time. Leave it stored wet and it soon becomes a very unattractive proposition - as will its contents.
The invigorating smell of the seaside can pall quite quickly. Items that looked so pristine when you packed them on a Friday night might be considerably less attractive when you unpack them the following Monday.
Consider too that any bag will need to be rinsed with clean fresh water and dried in a well-ventilated place. Some are equipped with drain holes that make them easier to wash. Of course, water can also enter through these holes when less than welcome.
If you think it's time to buy a new bag, weigh up the options carefully. Casual observation of the luggage belt at an airport when lots of divers are disembarking will make you painfully aware that no bag lasts forever!