SCP Foundation

There wouldn't be any SCPs permanently contained on board I don't think, and I imagine they wouldn't be capable of containing more than two or three especially dangerous SCPs. Also, I may have exaggerated the size a little bit.

It's been established that the Foundation has a fleet of naval vessels under its command, right? Maybe this could be the most advanced of their vessels. It could serve a multitude of purposes. It could get called in to transport any SCP that's too dangerous to just be locked in a crate and flown across the ocean. At times it could act as a research base for identifying, tracking, and studying aquatic SCPs (which I do need to read up on). There also clear tactical advantages to having a sophisticated stealth submarine in their arsenal, which I imagine would be armed with nuclear warheads in case final contingencies need to be enacted. In general, I think its greatest asset would be its adaptability.

I was also thinking there could be some backstory where it was the pet project of one O5 member, but now it's considered an impractical use of resources, which means the crew would have to learn to be self-sufficient and not rely on the Foundation for help at times, even though they do go up against highly dangerous and poorly understood threats on a regular basis.