Hi XP Dude, Cilento? that's in the south of italy. Not my waters, but i can give you pretty detailed information.
Yes, spearfishing is allowed on almost all the park's coastline, except around places called Camerota, Baia Infreschi and a cape called Punta Licosa that's a protected sealife sanctuary (no spearing, no boats, no swimming there). The best place for spearfishing are places called Acciarola (sargo, bass, gilthead) and Palinuro (groupers, dentex, amberjacks). Following full review of best park's spearfishing spots.
1- between the town of Agropoli and Ascea: GOOD, but that's where forbidden Punta Licosa is located. The surroundings are interesting. In Agnone, zone called Ripe Rosse, there's good sahllow water spot with rocks, green (Poseydonia) and sand: octopus, cuttlefish, moray eels, curvinas. Nearby better places: Pioppi and Acciaroli. Similar to Agnone but with better fish (big sargos).
Stay away from the line between Casal Velino and Ascea: dirty water, no fish.
2- From Ascea to Palinuro: VERY BEAUTIFUL, especially from Palinuro: caves, corals, grouper, dentex, gilthead and Amberjack, especially around a beach called Spiaggia Marinella at Palinuro. Then from Ascea Marina, Pisciotta e Caprioli, sand and rocks, octopus. The best is the line between Palinuro - Camerota - Sapri - Maratea. Beware forbidden areas Camerota and Baia Infreschi.
Hope this helps, ciao