The problem with maritime operations are bubbles (Picture 1) Kimmo Huosionmaa The idea of the scuba diving equipment, what recycles air thru the active carbon filter would not be new. It bases the idea of the submarine, what would use the diesel-motors under the sea, without the need to use the snorkel. This equipment is known as closed cycle diesel system, and the idea of this thing is that exhaust gas from the machine would be driven thru the active carbon filter. This filter would separate the carbon from the exhaust gas, and then this submarine could operate a long time before it must get back to surface. In the tests what the Soviet Navy made in 1950's the filter filled with carbon dust, and that caused the bad situation in the boat, because exhaust gas was polluted the air in that submarine. The better systems have particle filter, what would give extra time to use the carbon filter. The scuba diving equipment what uses so-called closed cycle is the very re...