They can be anywhere in the whole Skull Island (Waponi Wu [spelling?], the lighthouse, Shady Hollow, or wherever the quest says they are. If there is a circle with arrows that doesn't tell you where to go, then that means you don't have access to that area. So, if you are a free-to-play pirate, you cant find all of them.
Golden Chris Silver Level 35 ...i am gold, but yet silver
It sounds like you are looking for small piles of smelly bananas. Try going down the stairs, past Blind Mew and the dock gate, through the water, past the Krok with the transportalator, turn right and cross a hanging bridge and take the path. I bet you will find one. Once you have seen one, it gets easier to spot the others because you know what you are looking for.