If you're okay with thai dramas, there is Rak Nee Hua Jai Rao Jong. Nearly the whole drama is set in a desert island. It's about a model nearly raped on a yacht. She escapes by jumping in the sea and tries to go into a man's boat. But they both fell into water and end up on this desert island, chased by the henchmen of the yacht owner. Lot of yelling, be warned. But very beautiful scenery.
And then, I didn't watch them but I could find a few dramas on MDL with "Beach" on the summary :
- Beach Boys
- Let's Go to the Beach
- Bloody Beach
- Taiyo to Umi no Kyoshitsu