A scuba cylinder lower side mounting system employs two mating parts to secure the lower portion of a scuba cylinder to a diver's torso, the first affixed to either side of any side-mount or back mount Buoyancy Control Device utilizing a web waistband. A web cylinder band or stainless steel hose-clamp secures the second part to any scuba cylinder. The two parts are engaged whether in or out of the water by inserting the second part into the first and pivoting the cylinder at the point of attachment. Existing arrangements to position the cylinder valve near the diver's armpit will keep the system locked in place. It may be disengaged before entering or engaged after exiting confined underwater spaces without reaching between the cylinder and diver's torso. The system keeps the cylinder close to and aligned with the diver's torso regardless of the cylinder's change in buoyancy or diver orientation.

A back pack for an underwater breathing gas tank is provided. The back pack includes a tank mounting structure having a front surface facing away from an underwater breathing gas tank when an underwater breathing gas tank is operably mounted to the tank mounting structure. The tank mounting structure defines a recess. The front surface defines an opening of the recess. The tank mounting structure defines a bottom surface of the recess opposite the opening in the front surface. The back pack includes a strap and a buckle. The buckle has a latched state for securing the strap in a fixed position for securing an underwater breathing gas tank to the tank mounting structure. The buckle, when in a latched state, is positioned at least partially within the recess.

Disclosed is a support frame for a breathing apparatus comprising a cylinder cradle for supporting a compressed gas cylinder, a cylinder-retaining strap having a first end secured to the support frame at a first fixing point and a second end adjustably secured to the cylinder-retaining strap between the first and second ends, wherein the adjustable strap loop is secured to a second fixing point so as to form an effective strap length between the first and second fixing points, and a releasable third fixing point, wherein the effective strap length is adjustable by adjusting a position of the second end along the strap to thereby adjust a size of the adjustable strap loop, and releasably securing the adjustable strap loop to the third fixing point.

A pressure reducer for a self-contained breathing apparatus (SCBA). The reducer may include an integrated pneumatic alerting device with an upstream antechamber, and an integral refill air passage with a first end that is fluidically connected to a refill air inlet of the reducer and with a second, opposing end that is fluidically connected to the upstream antechamber of the integrated pneumatic alerting device.

A backrest for a scuba diver comprising: a strap, having an upper right portion fitting around the diver's right shoulder, an upper left portion fitting around the diver's left shoulder and a lower portion fitting around the diver's abdomen, a right adjustment block between the upper right portion and the lower portion, and a left adjustment block between the upper left portion and the lower portion. Each of the adjustment blocks has a first pin engaged in a first loop of one end of the upper portion, a second pin engaged in a second loop of one end of the lower portion, a clamp clamping the lower portion of the strap to block the sliding of the end of the lower portion of the strap around the second pin, and a handgrip actuating the clamp between blocking and unblocking the sliding of the end of the lower portion of the strap around the second pin.