Croatian beaches are rock or pebbles, except for few exceptions. The sea is almost everywhere crystal clear, especially on island shores. The coast from Rijeka to Zadar is high on the sea, with a few resorts at major villages like Paklenica, Senj and Crikvenica, but I've not been there since many years so I can't really suggest any of them. My favorite place is the island of Rab, just half an hour by ferry from the coast, which by the way has also a sandy beach at Lopar. Going up north, Opatija (near Rijeka) used to be a 19th century upscale resort and a popular destination before the war 1991-1993 but now I have heard it's not very appealing. If you're ready to drive a little farther, the rocky beaches close to Pula (Medulin, Veruda) and up to Rovinj are wonderful and offer any kind of accomodation.

Bye

Paolo Trieste, Italy (less than 100 miles from there)