No. You do not dive down to 80+ meter for an industrial size job, involving the placement of hundreds of pounds of explosives in eight individual charges on very sturdy pipelines, from a sparsely manned boat. Such deep dives require special gases, special breathing equipment,

Actually you could do this dive on air, but you'd be high as a kite from nitrogen narcosis. Oxygen doesn't start to get toxic until around 300 feet.