This one came as an uncertain city, but I'm sure it is a semis of Lucania Paestum (Poseidonia).
The problem is, (Yes Bob, another, but hopefully not unsolvable mystery.) I have only found a couple of coins that match, and both have the inscription CN TEV above the prow. This one reads CN.T.V, or so it would appear. (Dots or pellets between the second and fourth letters.) Could the third character actually be a T+E monogram? There should be PAES in the exergue, but it is illegible.
Is it just a variety of this attribution, or have I got it wrong?

Lucania, Paestum (Poseidonia) AE Semis. C. 2nd Century BC.
Obverse: Laureate head of Poseidon right, trident at shoulder; S (mark of value) behind. Reverse: CN.T.V above prow right, between two dolphins. Bronze. Diameter: 15 mm. Weight: 3.7 gr.
Ref: Crawford, Paestum 22/1; HN Italy 1231.