My team is going to arrive at an underwater research facility. Much like the one in Bioshock. (Containing droid enemies as a big bad nemisis etc) but I'm looking for good ideas for water based minions or rivals (not dionagas) something that may be able to enter an underwater facility via a breach in the hull. Please let me know what you come up with. It doesn't need to pertain to Star Wars universe per se but if you have stats that could be used it would help greatly

Giant crustaceans for armored threats that prioritize players that have unhealed crits.

• A troupe of electric eel-like creatures takes an interest in any character with powered up gear on them.
• A local group of semi-sentient cephalopods is offended by the droid presence of the research facility on their hunting grounds, and the PCs just happen to cross paths with them when they're preparing to attack - with stone tools.
• Two giant leviathans engaged in a mating ritual threaten not only the PCs but the entire facility with their violent throes.
• An unexpected eruption opens fissures in the sea floor that spew ash-laden, super-heated water well above the surface of the sea.
• A giant storm is passing overhead, causing dangerous currents and twisting tornado-like eddies to wreak havoc.

Hope that helps!

Have you got Strongholds of Resistance ? There's some good stuff in there including giant eels and cetaceans, as well as weapons and vehicles designed to be used underwater. Nexus of Power also has a few things, like the Naboo sea monsters from Ep I.