While the sub-sea tunnel deepest point is 165 meters ( 541 ft ) below sea level , the deepest sea depth is 40 meters ( 130 ft ) .
The minimum rock coverage is 40 meters ( 130 ft ) .
While the sub-sea tunnel deepest point is 165 meters ( 541 ft ) below sea level , the deepest sea depth is 40 meters ( 130 ft ) , and the minimum rock coverage is 40 meters ( 130 ft ) .