to get all the three items you needed too beat coordinate clues you should go like this:
1) professor at observatory. he will give you your first item, a dont remember which
, then go to port khazard (right east from observatory). you will find it easy because you cant go more east then that
2) at port khazard you should talk to a guy at the docks. he will give you your next item, dont remember wich either
3) go back to the observatory (or clocktower, dont remember which) and get you last item, dont rememebr which
, now your ready to hunt treasures for real!
*It was a while ago i got those stuff so i dont remember in which order I got them and where the last one was, at observatory or clock tower
, anyways, hope you find your stuff!
~Hello5000