There are two ways to carry your tanks into a cave. Although the side mount is currently less popular, it’s growing fast and will likely replace traditional back mount setups in the future. With a tank carried under each arm, alongside your body, and two independent air supplies, what may look awkward on the surface is a very comfortable and versatile system underwater. Sidemount does take a little getting used to, particularly swapping regulators every so often to ensure equal gas usage.
Traditionally, cave divers have used back-mounted twin tanks. Although they can be prohibitive when trying to squeeze through a small space in an advanced cave, back-mount tanks are more than adequate for most dives. You’ll also need three dive torches. Buy a specialized cave-style torch for your primary light source. Instead of concentrating on the lumen power, you should check how the beam is focused. A dimmer light with a focused beam will be far more useful in a cave than a bright, wide-beamed video light. Your other dive torches are backups and can be any style. Finally, you will need multiple reels. It is best to talk to your instructor before purchasing these, though, to ensure that you’re getting the correct style.