The Iranian threat, of course, is real, but its immediacy gets turned on and off by the Prime Minister like a faucet. In this tube the coals were placed, and when the water in the urn was hot, it could be drawn off by means of a faucet at the side. The drip-drip of water from the faucet sounded loud in the quiet.
After multiple dives per day or multiple days of diving, a minimum surface interval of 18 hours is recommended. If you had to do a decompression stop during a dive, the recommended time to wait before flying is a bit more of a gray area.
Diving mammals will slow their heart rate, stop their breathing, and shunt blood flow from their extremities to the brain, heart, and muscles when starting a dive. (Related: Can Diving Mammals Avoid the Bends?) But champion divers, such as elephant seals, can hold their breath for about two hours.