When diving too deep, scuba divers can experience a temporary impairment of mental functions. This is known as nitrogen narcosis and it occurs when the absolute pressure in a diver's air tank $($which is in equilibrium with the surrounding water$)$ exceeds approximately $700000$ Pa$,$ because the nitrogen in the air tank becomes poisonous.

How many meters below the surface of the water can a diver go before risking nitrogen narcosis? Take the density of ocean water to be $1030$