The pressure due to the depth in a liquid can be calculated as:
P = ρgh; ρ is the density in kg/m³, g is the acceleration due to gravity in m/s² and h is the depth in the fluid.
ρ = 0.65 g/cm³ = 650 kg/m³
P = 650 x 9.81 x 3
= 19100 Pascals
Pressure in atm = 19100/101325 atm
= 0.188 atm