Yangtze

The Yangtze is a Liao-Class Type 113 Chinese nuclear-powered ballistic missile submarine commanded by Captain Zao. When first discovered by the Sole Survivor in 2287, it is lodged in the shallow waters of Boston Harbor south of Boston Airport and northeast of the Four Leaf fishpacking plant.

Background
Sometime before the Great War, the Yangtze was on deployment with a payload of six strategic nuclear SLBMs and an unknown number of tactical nuclear missiles and torpedoes. When the Great War began, the Yangtze 's captain obeyed his orders to fire the submarine's strategic nuclear weapons at their targets. All but one of the missiles were successfully launched.

Shortly after firing its strategic missiles, the submarine struck a mine that severely damaged the reactor and forced the vessel to seek shelter in Boston Harbor. The damage caused a reactor leak that immobilized the sub and ultimately killed or ghoulified the crew of approximately two dozen men, of which only Zao retained his sanity.

The submarine is not marked on the map until the Sole Survivor swims out to it. Upon discovery, the quest Here There Be Monsters will automatically be started if it hasn't been received already from Donny Kowalski near the Shamrock Taphouse.

Layout
The Yangtze has three large propellers, with one on each side and a third under the reactor control room, as well as a smaller propeller at the rear of the submarine with the rudder. Upon entering the ship, the first room the Sole Survivor comes to is the bridge where Zao is located. Down the stairs is the reactor control room, with a small radio room on the left side ahead. Two doors on either side of the room lead down short stairways to similar small rooms with large machines behind cage walls, presumably the propeller drive shafts.

Behind the reactor control room and under the bridge through a southern doorway is a room with machinery and instrument panels. On the west side of the room is Captain Zao's quarters, and on the east side is the officer's mess. North of the reactor control room (through the terminal-activated door) is the upper reactor level, which contains a door to the north and a stairway on the west side leading down to the lower level. The lower level contains reactor machinery, with a Master terminal-locked door to the north, and two doorways to the south leading to the engine room for the lowest of the large propellers. Stairwells on either side of the engine room lead to the flooded lowest level.

North of the reactor room on the upper level is a small room that contains two decontamination showers and an Expert terminal-locked door with a stairway to the lower level. There is also a small science lab with a chemistry station through a doorway to the west. Continuing north (still on the upper level) is the mess room, galley, and food storage (the small room opposite the galley). North of the mess is the crew quarters, containing 80 beds (configured in eight stacks of three and fourteen stacks of four) with three lavatories. To the west of the crew quarters is a laundry room, and to the east is the infirmary.

North of the crew quarters are two doorways that lead to a single stairway down into a room on the lower level that contains machinery. From this room, a workshop containing a weapons workbench is to the east, and a storage room with toppled shelving is to the west. The next room to the south contains a doorway on the east side leading to the armory, and a hallway to the south leading to the silo room. The silo room contains six missile silos, with three along each side. Each silo has an access hatch that allows the crew to access the SLBM inside. All are closed except the one to the west with the missile that failed to launch. The next room to the south is a small room before the reactor room, containing a terminal-locked door to the stairway to the upper level.

Notable loot

 * Submariner uniform and submariner hat - Worn by Captain Zao.
 * Zao's sword - Possible reward for completing the quest. Only obtainable if all Speech checks are passed when first requesting a larger reward near the start of the quest.
 * Chinese officer sword - In the captain's quarters, on a desk.
 * Two fusion cores - One is in a box underwater on the east side of the lowest level of the engine room, just past a skeleton lying on a barrel. The other is inside an open footlocker in the crew quarters, near the Nuka-Cola Quantum.
 * Vault-Tec lunchbox - In the galley, on the table in the southeast corner.
 * Nuka-Cola Quantum - In the crew quarters, next to the bunk of the dead crew member holding a Nuka-Cola truck.
 * Stealth Boy - In the armory, inside the Master terminal-locked cage.
 * Submariner hat - In the silo room, worn by the first mate, now a glowing one.
 * First mate's password - In the silo room, on the first mate.
 * Warhead - In the silo room, in the capsule on the west wall.
 * Hazmat suit - In the silo room, in a locker to the southeast. The door to the locker must first be manually opened to reveal the suit and other minor loot.

Related quests

 * Here There Be Monsters: Living on the ocean shorefront is a boy named Donny Kowalski, who asks the Sole Survivor to help him determine what he has been seeing out in the water recently.

Companion comments

 * When at this location, companions make comments, which are activated at three locations: the bridge, the engine room, and after placing the warhead in the reactor.

Appearances
The Yangtze appears only in Fallout 4.

Behind the scenes
The Yangtze is the longest river in both China and Asia.