bell, checks that the bell is clear to be lifted, and report back to surface that the bell and divers are ready to start the ascent. Routine closed bell procedures: Locking out of and into the bell – Equalising the interior pressure with the water, opening the lock and entering the water, followed by checking the bell and proceeding to the worksite. Later returning to the bell, exiting the water and closing the lock to achieve a pressure seal. Tending the working diver – Management of the working diver's umbilical by the bellman Operation of the closed bell gas panel – Saturation decompression – Decompressing back to normal surface pressure after a dive where all tissue compartments have saturated with the inert gas in the breathing mixture. Emergency procedures These are the procedures that the diver is expected to be able to follow in the event of a reasonably foreseeable contingency. Some occur quite often such as the loss of grip on the mouthpiece in scuba diving, and are therefore usually well practiced. Others, like bailing out to emergency gas supply, should never happen if the equipment does not fail and the dive is carried out according to a good plan, and must be practiced as an exercise to maintain the skill or as part of pre-dive checks to ensure that the equipment is functioning correctly, as failure to perform correctly could be fatal. Emergency procedures are procedures to recover from a contingency that could be life-threatening if not responded to promptly and correctly. Some are trivially easy for a skilled diver. They include regulator recovery, clearing a flooded mask or helmet, bailout to emergency gas supply, emergency swimming ascent (for scuba), bell abandonment, shedding of weights (scuba), breathing off the pneumofathometer hose (SSDE), and switching over to onboard gas (bell diving). In cave or wreck diving, finding a lost guideline and finding the other end of a broken line are also emergency procedures. Scuba emergency procedures: Regulator clearing – Removal of water from the interior of the demand valve mouthpiece. Vomiting through the demand valve – Clearing and flushing the demand valve after vomiting underwater Regulator recovery – Finding a dislodged demand valve and returning it to the mouth. Stop freeflow - Correcting a demand valve malfunction that provides a constant high gas flow. Bailout - Switching to emergency breathing gas supply. Bailout to open circuit - Switching to