I wrote about and defended space pirates. I wrote about cutlasses in boarding actions. I wrote about ghost ships of space and yet I forgot one of the most improbable yet enticing nautical legends that is just waiting to be transferred to outer space. I refer to the Sargasso Sea.
The Sargasso Sea is the only sea on earth without a coastline, bounded instead by ocean currents and wind patterns in a relatively calm area of the North Atlantic off the east Coast of America. The currents and wind cause an accumulation of Sargassum seaweed which give the sea its name. It is also the site of The Great Atlantic Garbage Patch which must make the World's largest ball of yarn look like a real tourist attraction.
(Sorry no photos on Wiki of the Garbage Patch)
Fiction in a variety of media portray the sea as a region where ships became entangled and trapped in the seaweed becoming a 'floating land of death and decay,' to quote Ms. Norton. She brilliantly took hold of the idea and transferred it to her seminal novel Sargasso of Space a whole planet of wrecked starships!
This is a good thing mind you as it got Jonny and Team Quest to fight evil frogmen with a deadly super weapon. Sending them to investigate the Great North Atlantic Garbage Patch is just lame and I'm sure Dr. Benton Quest has better things to do.
(Saved by Hammer Films! Take that ball of yarn!!)
Everything is better in space so Sargassos, vast fleets of derelict starships are often invoked. Star Trek: the Next Generation invoked this idea at least twice that I recall. In a roleplaying game it most certainly rocks because as my oft time partner in crime Raymond McVay notes a starship is just a mega dungeon. What better than to have several dozen or hundreds of dungeons just floating along that you could practically reach with a rocket pack or a good push off a hull?
(Raymond McVay: making RPGs safe for hard science for a while now!)
I hasten to point out if one ghost ship is awesome a dozen or more should have your players twitching in rapture (that is a sign of joy right?) Picture this in your next game:
(Less captions and more holes and cobwebby stuff. Yes I'm making space spiders a thing now. Otherwise the
Mynocks(TM) space bats will breed unchecked! by DirkLoechel at deviantart.)
Okay now hold up a minute. Put down the cutlass. There are a few things to consider in creating a Sargasso.
How Did It Get There?
What destroyed or depopulated all those ships? Was it an alien trap? Plague? Local conditions? All these reasons are good but there are problems with each. If it was a trap how did it get so many ships. You'd think after SAR and salvage ship hulks started piling up someone would investigate.
If it was a fast acting plague how did it get to so many ships and incubate undetected to burst forth at once? A bioweapon is a possibility. Kill the crew, do a decon, and take over the fleet unless the fleet officers decide to retreat to a remote location and await a rescue that never comes.
Rogue AIs are another possibility. The AIs take a fleet over and jump far away from other fleets where they sit and infect other ships that come too close. This or plague might both be examples of super weapons and would be great ways to trap some you would be salvage mavens. You need to find the AI backdoor or the antidote or shut off the tractor beam!
The derelicts might be dragged to one place by government types for safety and because the government never throws anything away (including incumbents it seems). But in that case most likely everything of value has been stripped. People do make mistakes though. Guards are also a possibility and you lose a lot of the charm of a mysterious wreck ... cause of destruction unknown.
Space Is Not an Ocean!
Space is not a f#$%ing ocean. Why then is your group of derelicts just floating there? It's more likely they are orbiting something. A dead planet makes for a nice backdrop. Optionally they could sitting things out at an L-5 point. Otherwise they will either drift apart or eventually attract each other and clump together or violently collide. There's a finite limit to the time these hulks will be close together.
Speaking of which ever hear of Kessler Syndrome? There's no vaccination for that. Over time impacts with derelicts will create debris which creates more debris in a rapidly spirally cycle that will make approaching the fleet fell like going through a sandblaster. Of course the referee might like that.
Optionally your fleet could be grounded on a planet, a junkyard if you will. then you don't even need a ship to get to different hulls. You could walk (spacesuit optional.)
Where Is It Located?
It should be remote. Remoteness is very useful to establish a feeling of horror. If it is remote the trap origin runs into difficulty. Why is it so far off the beaten paths yet able to have trapped so many ships? Either it has a powerful lure or has operated for centuries. Even so after a few ships go missing the Navy will probably come around and blast whatever they can't understand. Also in many settings ships file these things called flight plans with their destination and estimated arrival times listed. A bunch of missing ships will eventually send a signal in some office somewhere. Again a trap working intermittently over years or decades might escape detection. All this becomes much easier with a 'remote central government'. They won't notice anything less than a sector fleet missing.
If you aren't too hung up on the science the local conditions could impede travel. An exotic nebula could drain power or some such. Jerry Pournelle did a great hard SF look at a fleet of trapped ships in He Fell Into a Dark Hole (1973).
Who Is There?
Zombies? Survivors? Hermits? Is there anyone calling the bunch of wrecks home? They might need rescue. They might be competition. They might want intruders dead and be batshit crazy. Maybe a bunch of space pirates call the fleet home and does not welcome you meddling kids (and your talking dog!) Perhaps other fortune seekers are there already and laying claim to the fleet.
Note that in modern maritime law a ship that is abandoned becomes the property of the first person to put boots on deck. If the claimers leave the ship then it becomes fair game for the next person to put boots on the deck. A salvage crew might claim the entire fleet but they'd only have claim to the hulks they actually occupy. In maritime law even leaving a mascot onboard means the ship is crewed and anyone else boarding without permission does not have a claim. That might not be the case in future space law. The salvagers might also decide a colony of giant space spiders makes a fine group of mascots and simply let them breed there until they blow the airlocks when they are ready to salvage the ship.
Modern space law says that no you may not take over an unoccupied vehicle you enter. Developed nations also frown on scooping up satellites from orbit.