Marine Cloud Brightening (MCB) has the potential to mitigate the effects of climate change at a reef scale by increasing the reflectance of low-level maritime clouds and cooling the ocean. MCB consists of dispersing a plume of sub-micrometre seawater droplets over the ocean, which evaporate and generate nano-sized sea-salt crystals that disperse through the atmosphere until some are incorporated into clouds. This droplet evaporation could produce a negatively buoyant plume hindering the ability of those particles to reach cloud height, hence, reducing the effectiveness of cloud brightening. The dispersion of those aerosol particles has not been validated with empirical experiments and only few studies have considered the influence of the initial evaporative phase on the vertical mixing of the plume. Here we describe the characterisation and dispersion of the sea salt plume in the vertical and horizontal dimensions. We use airborne systems to characterise particle emissions and measure particle concentrations at different heights. Results show clear evidence of the dispersion and vertically mixing of the plume from the sprayer source, with a strong dependency on atmospheric conditions. This study contributes to the general understanding of aerosol dispersion over the reef, and to the potential implementation of MCB over the Reef.