In this paper, deployment strategies of underwater sensor nodes and gateway nodes for two-dimensional communication architecture in Underwater Acoustic Wireless Sensor Networks (UWSNs) are proposed. In the sensor deployment strategy, underwater sensor nodes are deployed in two rows along the coastline, which is of complete coverage and connectivity, localization available and scalable. In the gateway deployment strategy, the gateway deployment is modelled as an optimization problem, by finding the locations of underwater gateway nodes required to achieve a given design objective, which can be minimal expected delay and minimal expected energy consumption. We measure the performance of the strategies by extensive simulations using the OPNET network simulator.