Dikes or levees act as barriers to contain large amounts of water. An old fairy tale concerns a boy who saved?

Holland from flooding using his finger to plug a hole in a leaking dike. Consider that this hole was 4 m below sea level (density = 1030 kg/m^3) and the boy's finger had a cross sectional area of 3 cm^2. Use the atmospheric pressure of 101 kPa to find the amount of force the boy had to exert.