Casino hack: Casino frequenters can get a hole punched in their room card and a free lanyard from the casino staff for easy play without forgetting your card in the slot machines.

Bonus internet: Many lines offer free minutes if you sign up for an internet package on the first day of the cruise. You can also get discounts by signing up for your Wi-Fi package online before your sailing.

Day one spa discounts: Cruise ship spas often offer discounts for first-day and port-day treatments. Stop by the spa, or check your daily newsletters to find out about deals.

Presentation reruns: If the port talk is at the same time as your massage, don't worry. Presentations and audience-participation shows are often re-broadcast on the ship's channel on your in-room TV. You can still catch the recording if you miss the live show.

Complimentary spa showers: Use of the showers, saunas and stream rooms not located in fancy thermal suites is free. Showering in the spa can often mean access to more clean towels, fancy toiletries and bigger shower stalls -- and prevents fights over who gets cabin bathroom access first. Using the free saunas is also a great remedy for that inevitable vacation head cold that stuffs you up.

Show up to sold-out shows: If you want to see one of the big-name shows on Royal Caribbean or Norwegian (like "Mamma Mia" or "Rock of Ages"), but tickets are sold out, don't fret. Many people reserve the free tickets but don't show up, so if you get in line prior to showtime, cruise ship staff will let you in if seats are available.