Laser driven ion acceleration arises from charge separation effects caused by an ultrahigh intensity laser pulse. Limited mass targets confine the accelerated electrons within the target size and prevent the large area spreading seen in extended foil targets. Furthermore, if the target size is smaller than the laser wavelength and focal spot diameter, homogeneous heating of the target is ensured. Observation of quasi-monoenergetic protons in the interaction of a high intensity high contrast laser pulse at 5×10 ¹⁹ W/cm² with 150 nm - diameter water droplets is investigated. An ensemble of such objects is formed in a spray. Quasi mono energetic proton bursts of energy E ∼ 1.6 MeV are observed and are associated with a specific ionization and explosion dynamics of the spheres.