When down, start looking for a new place to visit. Unless you like concrete.
Go out past Puerto Plata, past Cofresi, past Amber Cove. You'll see a small gas station, take that road to the right down the coast towards the village of Guzmancito. About 20 minutes from Rt 5 there will be a beach on your right side that is very similar to Sosua Beach. Vendor shacks, trashy, shallow dug latrines, busy on Sundays.