SPOILER Questions About Fantastic Voyage

So I'm on the island where you need to collect several items, but after a while of searching, I've only managed to get the muttons and berries. Can someone tell me how do I get coconuts and also how to break the giant boulder? I have black powder, rock dust, saw dust and gritty sand which I've collected thinking that it would help.

 

When looking at the island from the water where the ship crashed just to the left is a big coconut tree with wooden slabs you can climb on. There is a level 0 coconut you can kill. Just a little bit left of that tree is a cave with mushrooms. Be aware you need the 'edible' items (brown) and not the toxic (red). The other items you collected are indeed for the TNT and should start after you finished the meal.