of water inside and outside of the confinement 2 form a system of communicating vessels the lesser average density inside confinement 2 has to be made up by increased height accordingly as shown in fig1 the combined height of solutions 3 5 and 10 exceeds surface 1 of the surrounding lake by h o the hydrostatic pressure on both sides of confinement 2 is equal to the bottom edge a of the hull 2 while above it the pressure exerted on it from within exceeds the counterpressure from without in consequence of and in proportion to the difference of height h o between the upper surface of wind mixed layer 10 of the water inside confinement 2 and upper surface 1 of the surrounding lake as is well known the static pressure at a given depth is the product of the average density at the depth and the depth itself multiplication of the product by the gravitational constant providing the proper dimensions because the density is uniform outside the hull the pressure outside varies linearly as indicated by curve b the static pressure inside the hull however varies typically as indicated by curve c with the pressure inside and outside the hull being equal at bottom edge a as a consequence of the greater height of liquid inside the hull and the density profile of such liquid the inside static pressure of a given depth throughout most of the depth of the hull will exceed the outside static pressure producing a pressure difference indicated by curve d the resultant pressure which is normal for the hull surface creates a circumferential.