Complex sentence: Both buddies check each other's first and second stages, confirm the locations of their octopuses, and proof check by breathing from each other's equipment.Know SAC rates and how much air you and your buddy have before you get wet.
Split into simpler sentences: Both buddies check each other's first and second stages, confirm the locations of their octopuses, and proof check by breathing from each other's equipment. Know Surface Air Consumption (SAC) rates and how much air you and your buddy have before you get wet.