The wood types for ships are defined as "Oak", "Pine", and "Ash" by str_ship_wood_1 - 3. Assuming it is right, the "beech" in following two texts contradict with it, and these "beech" seem to have to be "ash".
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dlga_port_chief_info_c_2:port_chief_info_main
The second important factor is the type of wood the ship is made from. Ships made out of oak wood are the best ships, but are also expensive. Beech is cheaper, but it rots faster.
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ip_ship_info
... Finally the wood used for ship construction affects its durability. While ships made of oak wood are very durable, ships made of beech wood need to be repaired more often. ...
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- Game version (and steam or downloaded):
AWoIaF v8.1, Warband v1.167 downloaded
Fixed- All instances have been changed to Ash.