I don't think I'd trust using poisons on a ship - I don't know anything about poisons, though, so it's mostly that I'd have no idea what I'm doing...

[The final words trail off questioningly, looking at Sasuke in a way that asks if he knows any more than she does.]

Other than that, since we don't even know what size we're dealing with... tripwire's a good idea, that's easy enough and it works in confined spaces. A snare would work on something smaller, too.