Self-deployment of sensors with maximized coverage in underwater acoustic wireless nensor networks（UAWSNs） is challenging due to difficulty of access to 3D underwater environments.The problem is further complicated if connectivity of the final network is required.Propose a purely distributed node deployment scheme for UAWSNs which only requires random dropping of sensors on water surface.The goal is to expand the initial network to 3D with maximized coverage and guaranteed connectivity with a water surface base station.The idea is based on determining connected dominating set of the initial network and then adjust the depths of all dominate and dominator neighbors of a particular dominator node for minimizing the coverage overlaps among them while still keeping the connectivity with the dominator.Simulations results indicate that connectivity can be guaranteed regardless of the transmission and sensing range ratio with coverage very close to a coverage-aware deployment approach.