This is the description of a runescape quest: "Private's Treasure". Here I want to talk about the steps about finishing this quest.
Redbeard Frank is outside the bar in Port Sarim. Talking to one of the sailors along the dock, and it will cost you 30 runescape gold. Then, you should head to the bar, trade with Zambo and buy some Karamjan Rum. Return to Port Sarim and enter the food store. So go to Redbeard Frank and give it to him. Then, try to open the door again and search the crate. Now, you can get the rum, so go to Redbeard Frank and give it to him. Runescape accounts for sale is also a good choice for you! He will give you a key to open a chest in the Blue Moon Tavern. Go upstairs and open the chest at the south end with the key. "Private's Treasure" is one of these quests, in which you must get back a bottle of rum for a thirsty pirate. It may require some work to persuade him to let you know where, though.
You'll have to dig, Resume digging afterward to find the treasure chest. Now, congratulations! You have completed the quest with your buying runescape accounts.