After three days of playing the game, finally i finished Hidden Expedition last night (actually i didn't know if the game has only 15 dive and i stopped at Dive 14 the day before yesterday). The last task was very tricky, since after you had to solve 36 items, you will have to open the treasure chest which contains the lost crown and the captain save the combination number around the chest and you didn't get any clue (there's still a hint to be used but it waste a lot of time if you used it, so i suggest that you don't use it except for the last number). You will have to click most of the items and hopefully you can finish this game off. I had to restart three times before i managed to get the clue (did i forgot to mention that the items that holds the combination number was always changing?).
After finishing the game, you will find this screen: