The single most important piece of caving equipment is your light. Experts recommend that you bring three independent light sources. The most basic is the head-mounted lamp that straps securely onto a helmet. Other light sources could be handheld flashlights, glow sticks or small LED lights. You should carry a few extra bulbs and batteries for each light source.
Your helmet should meet the stringent safety standards of Union Internationale des Associations d'Alpinisme (UIAA) or European Community (CE) certification. And make sure your headlamp fits tightly and securely on the helmet before you leave the house.
What you wear while caving depends on what kind of cave you're going to visit. A lot of caves are pretty cold -- in the 50s Fahrenheit (10-15 degrees Celsius) -- so you'll want to dress in layers. The National Speleological Society recommends synthetic fabrics like nylon and polyester over cotton because synthetics tend to dry faster if they get wet and are more resistant to the scrapes and snags common to caving.
Find out everything you can about the cave you're going to explore. If there's a chance you'll get very wet, you'll want to bring a change of clothing. Some other clothing items you might want to consider are waterproof hiking boots, gloves, thermal underwear, and knee and elbow pads for extended crawls.
You'll need to bring enough food and water for the expected length of the trip and some extra, just in case. If you have a map of the cave, make copies and give one to everybody on the trip, even if you have a guide.
You'll want a small first-aid kit for cuts and bruises. Make sure that everyone brings any medication that he or she needs to take on a regular basis. You'll need enough large plastic garbage bags to hold any food waste and dirty clothing.
A general rule of cave conservation is not to leave anything -- including human waste -- in the cave, so everyone will need a plastic bottle for urine, toilet paper and a small, crush-proof plastic container for "number two."
Some other useful equipment for cave exploration is a camera with a flash (consider disposable models to avoid damaging expensive equipment), a magnifying glass, pen and paper, and the universal solution for any problem -- duct tape.
Now let's look at some important safety considerations when caving and the best techniques for protecting yourself and your group.