becomes available due to ambient pressure reduction. Cut free from entanglement. Ditch weights to establish buoyancy – Removal of some or all ballast weights to establish neutral or positive buoyancy underwater, or to establish positive buoyancy at the surface. Standardised emergency procedures used with manifolded twin scuba cylinders – Closing the isolation valve, or closing the left or right cylinder valves to identify and isolate a malfunction, and opening the valves as appropriate to make best use of remaining gas, and switching demand valves as required. Therapeutic recompression – The use of recompression to treat symptomatic decompression illness. In-water recompression – Recompression underwater to treat decompression illness or to compensate for omitted decompression. Surface supplied diving emergency procedures: Mask or helmet clearing - expelling water from the interior of a helmet or full-face mask. Bailout to scuba - Switching to scuba emergency gas supply. Bailout to pneumo hose – Using the pneumofathometer hose as an emergency gas supply. Switch to bell onboard gas - Switch to emergency on-board gas supply in case of surface supply failure or contamination. Abandon wet bell - Surface from wet bell which cannot be raised. Respond to heating water malfunction - Manage thermal imbalance due to inappropriate heating water temperature. Respond to dry suit flood - Manage insulation and buoyancy loss due to flooded dry suit. Respond to suit blowup – Prevent uncontrolled buoyant ascent. Respond to buoyancy compensator blowup – Prevent uncontrolled buoyant ascent. Respond to voice communications failure – Revert to rope signals. The dive may be terminated. Free a snagged umbilical – This could prevent the diver from surfacing. Manage vomiting in the helmet – Clear a helmet or full-face mask after vomiting inside it before breathing from the demand valve. Manage a broken faceplate – Unrestricted flooding of the helmet is a life-threatening emergency. The dive will be terminated. Flooding can be minimised by positioning the leak as low as possible and opening the free-flow valve. Wet bell emergency procedures: Dynamic positioning alarm and runout response - Dynamic positioning failure puts the divers at risk of being dragged by their unbilicals without warning, with a risk of snagging and rupture. They will return to the bell as a matter of urgency. The bellman will take up slack to help avoid snagging. Bell gas panel operation – The bell gas panel is used to switch to on-board gas supply if the surface