You've been considering a cruise but want to know exactly what you are getting — and there is a lot of misinformation out there. So let's break down some of the biggest cruise myths.

Being health-conscious will ensure that you don't gain unwanted weight on your cruise. — Britt Erlanson/Getty Images

1. The best deals are last-minute
You'll see cheap last-minute prices for some itineraries — such as a week in the Caribbean for $499 — as cruise lines try to fill space that hasn't sold. But these fares aren't necessarily a good deal for several reasons, the biggest one being that the best cabins sell out first. A better tactic is to book an early-bird fare, six to 12 months out. This typically lops 25 to 50 percent off the brochure price.

2. You'll get fat
Perhaps one of the biggest cruise myths is that you'll gain five pounds just by stepping aboard the ship. It's true that a crazy array of food is available 24/7. But cruise lines are aware that passengers are increasingly health-conscious. Menu choices reflect this, with plenty of low-cal, low-carb, vegetarian and other healthful options. Plus, you can work off your Baked Alaska splurge in the gym (some ships even have fitness boot camps) or on the jogging track.

3. You need to dress up
There will be some sort of dress code in the main dining room. But in general, cruising has gotten much less formal in recent years. Most nights you'll only need "smart casual" attire. And you can always skip the dining room for a more casual meal at a buffet or other laid-back venue — where a Hawaiian shirt is always appropriate.

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