Here There Be Monsters

Here There Be Monsters is a quest in Fallout 4.

Quick walkthrough

 * 1) Go to The Shamrock Taphouse and talk to Donny Kowalski on the dock at the rear of the building. Alternatively you can swim out to the submarine without even talking to Danny, upon discovering the sub, the quest will begin automatically. The periscope sticks out of the water off the shore from the dock, it's not hard to miss.
 * 2) Just out into the ocean is the Yangtze submarine. Investigate the submarine.
 * 3) Talk to Captain Zao.
 * 4) Get the dampening coil from Saugus Ironworks.
 * 5) Collect the nuclear warhead from the unfired ICBM in the submarine.
 * 6) Talk to Captain Zao.
 * 7) Replace the dampening coils and insert the warhead in to the reactor.

Behind the scenes
The name of the quest is a reference to cartographers often drawing sea monsters on unexplored areas of a map. In many cases, a phrase similar to "here there be monsters," such as the Roman "here are lions" (hic sunt leones), was written on the map as well.

Здесь могут водиться монстры