The weather is nearly always good in Campania. Since many of the interesting towns enjoy a coastal position it is often possible to combine a cultural break with sun and sea. Long sandy beaches are not typical for the region, but small sandy coves are found amongst the rocks.
If you are into snorkeling there is plenty of opportunity to explore the sea by the cliffs. Good places are found in the Cilento nature reserve, on the island of Capri and also on the Sorrento peninsula.