Hi paul, about ten years ago I went to Sosua which is nearby to Playa Dorada. I saw plenty of people beach fishing but mainly in the evening when its was empty and all the jetskis were gone. The hotel I stayed at even hired out rods but I didnt have a bash. I went snorkeling and the sea was chocka with fish, even came face to face withe a small baracuda only yards off the beach.

Hope this helps.