What You'll Pay: While many onboard activities are free, other special activities incur extra fees. Among them are fitness classes like Pilates, yoga and spinning ($12 to $30 per class); wine-tasting events; after-hours group babysitting for the youngest children (about $5 to $8 per child, per hour); behind-the-scenes tours; and bingo and casino play (as much as you're willing to lose). New attractions like laser tag, escape rooms and IMAX movies often come with an extra fee.

Savings Tip: You can certainly keep entertained with free activities. Attend the production shows, live-music performances, cooking demos, pool or trivia games and free lectures -- or simply spend your time chilling by the pool, reading a book or chatting with your travel companions. Many of the top entertainment offerings -- Broadway productions, onboard surfing and watersliding, live music and comedy acts -- incur no extra charges (though reservations might be required). If you're intrigued by the for-fee activities, set a budget and choose the ones you find most interesting. #inCruises