A bubble in water is an example of a scatter for which the refractive index of the core (gas) is less than that of the surroundings. So bubbles in water exhibit scattering phenomena which differs significantly from those for drops in air or solid particles in water. The scattering of bubbles in water as a means to detective the size of bubble has been investigated in many ways such as Mie theory and Davis’s geometric-optics theory. In this paper, a new physics-optics method was applied to manifest the scattering properties of a spherical bubble in water. The angular distribution of intensity of light scattered from a collimated beam that is incident upon a spherical air bubble in water is determined for any bubble with radius greater than a few wavelengths of the incident light. One external reflection, four internal reflections and four refractions are considered. The intensity of scattering light is tabulated and plotted as a function of the observing angle, the effects of the bubble’s radius, the electric field’s polarization of the incidence light and the wavelength of the incidence light on the scattering intensity distribution are also discussed.