To start off this fleet is designed for 80 Point games.
Being somebody who loves playing the cursed, but is cursed by their selection of game pieces i have come up with a few interesting fleets. This being one of them.
The idea behind this fleet is to intercept enemy gold runners using Sea Monsters. Meanwhile the locker can remain submerged and provide extra movement, firepower, and constant ramming when possible. Sargasso Nightmare gives both Sea Monsters a fast boost out into the game area where they will make their way to the islands being explored by enemies. The Hades' Realm and Nightmare are used as the cursed treasure runner/combat support. Since the Hades' Realm basically has to have a captain to be effective it works well as a hybrid ship.
The Locker is really the staple (flagship) of this fleet as it provides the "buff" that the Sea Monsters need to be effective. It also can ram enemy ships from below and slowly wear down the other fleet. Lastly, if the correct opportunity presents itself the Locker can come above the surface and use its ability to decimate injured or smaller ships, this isn't typically recommended because if the Locker goes down, so does this fleet.
Calim is a very important piece of this fleet as it has an insanely fast movement when within a L of the Locker. Calim will use its boarding ability to Ram smaller ships and board hopefully eliminating 2 masts in the process. Since Calim is one of the Sea Monsters with cargo capacity it will steal a treasure from said rammed ship if the boarding party goes as planned.
Calypsos has a pretty neat ability that plays into this strategy quite well. The underlying strategy is the same as Calim, however it just aims to eliminate good crew and/or steal treasure.
Hades' Realm is one of the most solid Cursed ships in my opinion and is a sweet hybrid. It is used to grab a few treasure and help out the Sea Monsters when possible.
The Nightmare basically avoids any conflict it can and instead tries to get gold from perimeter/nearest islands where conflict is unlikely.
Overall The Cursed are at a usual disadvantage but they are the best faction for Sea Monsters and as such i think it is fitting to find uses for them. This fleet can be surprisingly effective, provided nobody uses: Cancelers, Shooting at submarines, Cursed Conch (or anything that can mess with sea monsters & Submarines). This fleet struggles against big gun ships (The locker cant do much against 5/6 mast ships) and those should be eliminated first if possible. It isn't perfect (as no fleet is) but it can be very effective if used against the right fleet.