Had great fun running this as a one shot for my family. It has great art (mostly public domain I believe, but very well chosen and used) and layout. The locations and characters are few enough and simple enough that this is a breeze to prep for, and yet it's still open ended enough that there are many ways it could go depending on the party's choices.
One crucial recommendation: make sure that the party has a strong interest in saving the ship. The easiest way to be sure of this is to choose your hook carefully.
I used Cthulhu Dark rather than Knave -- to be honest, Knave is far from the first system I'd think to use to run this, and I welcome the news of a system agnostic version.
I think it would take most average groups about 2.5 to 4 hours to run this end to end. Obviously depends a lot on the system and group.
Definitely play at night for those spooky vibes. And have some stormy ocean sounds ready to enhance immersion.