if you get the chance, check out the forum at backstagejobs
- in the "getting work" section, there's a thread going about cruise ship tech work.
Lighting techs are a needed commodity! you do need to be able to program quickly (my line uses Hog 2 & 3's) and be able to bench and repair any fixture in your rig.
Can be a 12 hour day or more if a show or cast is getting installed - or a tech heavy act comes in, but I'd say 6-8 hours is more the norm if your rig is in good condition.
"Best" lines? That's subjective . . but the 'big' lines generally have the latest in toys and gear and the older the ship, the more you need to be up on repairs. Many techs will go for a line where they can get a cabin to themselves (not sharing with another)