This paper proposes an efficient 3D deployment approach for multiple UAV base stations, to maximize the probability of connections for users spread over a wide area. We consider covering a circular region, such as might apply in a disaster scenario affecting a city centre where terrestrial base stations have become inoperable. We compare two approaches to deploying UAVs. One is a regular triangular arrangement of UAVs and the other is an optimized circle packing arrangement. We start by considering a flying height optimized for a single UAV. We then show that both approaches can be improved by varying the height and flying locations of the UAVs, to expand the overall desired coverage area and overlap the individual UAV coverage areas. We show that the simple regular triangular arrangement can obtain superior connectivity compared to the circle packing approach, with significantly lower complexity.