Ships are classified as fishing ships, transports or warships.

There are 4 types of warships: 

Archer ships (such as the <link="proto:trireme">Trireme</link>) can defeat fishing ships and hammer ships.
Hammer ships (such as the <link="proto:ramming ship greek">Pentekonter</link>) can defeat siege ships.
Siege ships (such as the <link="proto:siege ship greek">Juggernaut</link>) can defeat archer ships, and are also good against buildings.
Only the Atlanteans can train <link="proto:fire ship atlantean">Fireships</link>, which can defeat siege ships.

On land, ranged siege units (the <link="proto:petrobolos">Petrobolos</link>, <link="proto:catapult">Catapult</link>, <link="proto:ballista">Ballista</link> and <link="proto:chieroballista">Chieroballista</link>)  can defeat ships as well as towers and other shooting buildings.

Greek Ships

<link="proto:fishing ship greek">Fishing Ship</link>
<link="proto:transport ship greek">Transport Ship</link>
<link="proto:trireme">Trireme</link>
<link="proto:ramming ship greek">Pentekonter</link>
<link="proto:siege ship greek">Juggernaut</link>
<link="proto:hero greek argo">The Argo</link>

Egyptian Ships

<link="proto:fishing ship egyptian">Fishing Ship</link>
<link="proto:transport ship egyptian">Transport Ship</link>
<link="proto:kebenit">Kebenit</link>
<link="proto:ramming ship egyptian">Ramming Galley</link>
<link="proto:siege ship egyptian">War Barge</link>

Norse Ships

<link="proto:fishing ship norse">Fishing Ship</link>
<link="proto:transport ship norse">Transport Ship</link>
<link="proto:longboat">Longboat</link>
<link="proto:ramming ship norse">Drakkar</link>
<link="proto:siege ship norse">Dragon Ship</link>

Atlantean Ships

<link="proto:fishing ship atlantean">Fishing Ship</link>
<link="proto:transport ship atlantean">Transport Ship</link>
<link="proto:bireme">Bireme</link>
<link="proto:fire ship atlantean">Fireship</link>
<link="proto:siege ship atlantean">Siege Bireme</link>
