Merchant of the Skies

If you follow the early series of quests that send you from island to island to deliver mail and whatnot you’ll eventually land on one that has a broken Lighthouse. Your uncle will send you a letter and I believe flying turtle man that roams the map will also speak with you about it.

You basically have to repair it 4 or 5 times, the first repair is with basic materials and your final is with materials from top of the tech tree.

I aggressively pursued this early on and kind of wish I had not, the completion doesn’t gate anything away from you that you can use early on anyway. I suggest your pursue this naturally. As you build out your islands.

Instead of an exact list of materials, with which you’ll be most familiar by the time you can complete the final repairs here’s the types of islands you’ll need to build out in order to do this: Wood, Stone, Sand, and Iron. I’d recommend you buy them and level them up with that priority.

Once you complete the final repair the quest will complete and the achievement will pop.

Note that there’s no other use for the Gears at your Iron island (save selling at the Bazaar) so you’ll probably want to turn off that production or sell that building after you get enough for the final repair.

A second note: The Lighthouse allows you to build Caravan Offices on your owned islands (so long as you can build a charging station first). Sadly this functionality is currently gated away from you until after you complete the campaign, though I think it’s probable that allowing them during the campaign will be a highly requested feature so it’s possible this will change at some point.