When a large bubble rises drom the bottom of a lake to the surface. Its radius double S. It atmospheric pressure in euqal to that of colurnn of colurnn of water height H then the depth of Lake is
$ p_1 v_1 = p_2 v_2 $ $ ( p + h \rho g ) {4 \over 3} \pi r^3 = p_0 \times {4 \over 3} (2 r)^3 $