TL;DR - 10/10 highly recommended. Freaked the players out.
Absolute gold. Ran this as a one-shot that managed to hold the players attention with rising tension as the hauntings got weirder (and the submarine got more wrecked). Strong 1889 vibes (the Netflix show)--and just like it we don't get an included ending (best to consider some options before running it). But on the plus side, the players talked for an hour afterwards imagining what *could* have been going on and what it really means.
For player creation, I showed them a map of the vessel and let them pick where each character lived. We ended up with a Cook (roll, for Kitchen! lol), Mechanic (Engines) and Comms Officer (Bridge). I also had them pick whether they were on the US or British inspector side (to hilarious effect!), and per the rules, let them come up with 2 underlings each to boss around. Played some spooky ambient underwater submarine music which greatly added to the game. Giving everyone a tutorial of "how to manage a submarine and keep it from sinking" (ie how long batteries/oxygen lasts) immediately hooked the players into the vibe of the game--I was surprised how interested they were in it.
Also used a Time Timer (physical timer) to set for the hauntings and other dangers, really added to the tension.