The Arctic Harbor is the only way you can obtain the very valuable good Promethium (eg., it will be required during Guild Expedition negotiations, if it isn't already required). When you open it, there are two main tabs: Harbor and Ship. After the first time, you'll want to open the Ship tab first and click on the Repair Ship button at the bottom. To repair your ship will cost you other goods. I actually don't know what happens if you don't repair your ship. I assume the price to repair it will continue to increase until the cost is prohibitive. After you repair your ship, click on the Harbor tab. There you will have to select crew members. You'll initially have 3 crewmen per voyage but that will increase to 4 or 5 eventually. Each crewman has a level and you'll want to increase it, when you're given the chance. Also, each crewman has liabilities and assets. Assets are how much extra Promethium they can provide and how much they shorten the duration of the voyage (initially, each voyage is over 24 hours and you will obtain at least 65 Promethium per voyage, I think. When the ship has returned to the harbor, you'll see a box like you do when you collect from your other bldgs.). Liabilities are the subtractions to your Promethium cargo and extra time added to your voyage. You'll notice an option at the bottom of the page that says "Exchange". If you press that button, the crewmen that you haven't already selected will be swapped out for others that are available. There's a limited number of crewmen but their number continually increases. However, only the first exchange is free. If you want to swap out the unselected crewmen a second time, it will cost you diamonds. Once you have selected your crewmen, you will be able to send your ship on its voyage to obtain Promethium. Bon Voyage!