The Semath River is a river in Araluen. It flows trough Araluen Fief and Castle Araluen. It is probably based on the real-life river Thames (their names are anagrams), which also flows trough the capital. The rivers delta and the river itself are protected by forts to stop a possible attack. 

After the Treaty of Hallasholm was signed, Erak, Will, Halt, Cassandra and Horace sailed on this river to Castle Araluen on Wolfwind