Turtles start arriving on the beach at 8 pm, and they keep coming till 4 am. The best time to spot the turtles is around 2 am.
Turtles may go to any area of the beach, but the best place is beyond a small stream. For this reason I recommend bringing sandals (not trek boots), bermudas, a T-shirt and a pullover. You should bring mosquito repellent, a flashlight and a raincoat. All your clothes should be dark.