I followed the crows nest shadow at 5. i cant figure out what to do from there.

Hint: you're looking for a buried treasure. You have already found its location. There is something in the vicinity that will help you dig it up.

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Spoilers for the solution to the puzzle
You need to take one of the brisance bottles (the explosive substance) from the stack nearby to the place that the shadow points to, then make it explode. You can throw a stick to the bottle to provoke the explosion.

Thank you, gamer. That's one obscure solution to the puzzle.