You will reach the harbour in day 3. Somewhere far right there will be some arcades.
You have to do 3 tasks :
1. hit the target at the Witch dunk 2000
2.hit 2 targets at the sailing man and then hit 4 of them across the level:
-for the first one go south from your position and a little east
-the second one is north from the initial position, up a ramp and a little west
-for the third one go west from the initial position down a ramp and south until you reach a car
- the forth is at the entrance in the harbour
3.hit the targets in the ground in a specific order : bottom left, bottom right, middle top, top left and top right
A visual guide :