This location is part of the quest “Hull Breach 3”. It is infested with various types of mirelurks. Use your VATS to locate the mirelurks hiding on the ground or from a distance. There’s a mirelurk king somewhere in the middle of the cove and will appear only when you get near it. Also, check out the houses nearby the Cove to find more containers and components to loot.
The NW shack has a mirelurk egg nest in the upper floor with the wooden crate. On the top floor, you’ll find a duffle bag, a sniper rifle on the chair, and ammo.
There’s a holotape (Family Announcement) in one of the shacks to the east, along the coast. There’s also a wooden crate and duffle in the same room. In the last shack connected to the walkway, you’ll find a weapons workbench, some components, and another holotape (Chores List).
One of the smaller shacks in the middle has a steamer trunk, some ammo boxes, and a holotape. (Husky Family Holotape). Continue to the last shack in the middle to find Bray Husky’s corpse and his holotape nearby.
There’s a radioactive waste processing facility NE of Haddock Cove surrounded by feral ghouls. Inside, there’s a locked terminal (requires key) and what seems to be a Children of Atom Shrine.