The rapid growth of IT technology has enabled ship automation systems to gain better functionality and safety with reduced costs and crew numbers. Nowadays, the remote maintenance services for the systems are required because a ship may be located in a very remote area. To provide the remote maintenance services, some issues such as how to collect the ship automation systems data, how to monitor a ship's data from onshore offices, how to get support from experts while sailing, and how to reduce the maintenance costs, should be addressed. In this paper, we propose a remote ship maintenance system for remote monitoring and diagnostics of ship automation systems, which is based on both a ship area network to integrate separate system networks and a ship-shore communication infrastructure to support a remote access using satellite communications. Finally, we present the function test to verify the applicability of the proposed system.