During your exploration of the Fallout 4 wasteland you might have come upon the wreckage of the USS Constitution. The ship is quite a sight, as few have seen a colonial era warship stuck on top of a building. If you haven’t located it, just leave now and try to find it, it is on the east coast of downtown Boston, just north of Goodneighbor and east of Bunker Hill. A giant wooden ship on top of a building is tough to miss, so just wander around till you find it.
Once you do you’ll be tasked with a few missions by the robot crew. The aim is to repair the ship so that it can once again resume its mission of protecting the people of the Commonwealth. We won’t break down the entire quest, as it is pretty straight forward and requires only a little bit of exploration. Instead we want to focus on the end of the USS Constitution mission.
Partway through the questline you will encounter the group of scavengers that have plagued the Constitution for months. They explain that they want what’s inside the ship, namely food, shelter, and wealth, but the robots won’t let them have it. They offer you a compromise. You help them take out the robots and they’ll split the bounty with you. It’s here where you have to make a choice, do you keep helping Ironsides and the crew of the USS Constitution or do you help out these scavengers.
We’re gonna get into spoiler territory here, so just be warned. Essentially, the best course of action is to agree to help the scavengers. This earns you the part you need from them without having to steal it or fight for it. After that you can actually decide which to go with.
If you side with Ironsides then you will gather the remaining parts and repair the ship. The scavengers will then attack just as it’s about to lift off. You’ll have to take them out, but that shouldn’t be too difficult thanks to the cannons mounted on the ship. Once defeated you’ll be given the Broadsider, which is essentially a mobile cannon.
This weapon is pretty powerful, but it uses actual cannonballs, which can be hard to come by. It’s also pretty tough to aim, but if you’re looking for another fun and unique weapon to mess around with, you can’t go wrong here. Finally the ship lifts off and…immediately crashes into another skyscraper. Head over there and go up the two elevators in the building and you’ll find Ironsides, boasting of the success of his mission. He’ll give you a hat, which offers a Charisma boost, and the use of his quarters. Not a lot of good stuff, but still better than going with the scavengers.
If you go with them you’ll sabotage the ship by taking the parts to their group first. Once the sabotage is set off you’ll have to fight the robots on the Constitution, which can be a lot tougher than fighting the scavengers. After you defeat them, meet back up with Mandy near Cabot House. She’ll then explain that they have decided not to split the loot with you. They’ll then attack, so just kill them and loot what you can off their bodies. The only real benefit here is that you can then loot the ship with a somewhat clear conscience.
So, to answer the initial question of who to side with in Fallout 4, it is obviously up to you. Morally it probably makes more sense helping other humans, but you’ll just end up having to kill them in the end. For the most good in the world, and for your character, I’d say stick with Ironsides.