Reaching Sosua beach is easy. From the centre of town, take Pedro Clisante Street where it begins next to La Roca restaurant. Alternatively, you can walk through the Beach Way plaza located right next to the Checkpoint Bar.
Sosua is roughly 20 minutes from Puerto Plata International Airport (POP) by taxi. Local guaguas (shared minibuses) and motoconchos also connect Sosua with nearby towns like Cabarete and Puerto Plata.
We went here last winter and it was exactly like you describe. The water really is that clear!
Great little guide, thanks for putting this together.