What is the external pressure on a submarine's hull at 5 meters?

P=1.01325*10^5+1020*9.806*5=151336 (Pa) =151.336 kPa

Since 1Pascal = 1.45 x 10(power of -4) lb/square inch

then P = 15.1336 x 1.45 = 21.94372 = 21.94b/sq inch