<p>You're off on a long-dreamed-of vacation, a cruise to sunny Caribbean islands. You're on a big cruise liner with a couple thousand other passengers. There are doctors and nurses on board, locks on your stateroom door, lots of public spaces, and ship personnel at your beck and call. Safety isn't something to worry about.</p><p>Not so, says Miami maritime lawyer Charles R. Lipcon in a new book, <em>Unsafe on the High Seas</em>.</p><p>''The problem is, people don't think anything bad can happen,'' Lipcon said in an interview. But as on any vacation, things can go wrong even on a cruise ship, he says, and passengers need to keep their guard up.</p><p>Most importantly, he says, don't leave your common sense behind.</p><p>''Getting on a cruise ship is like traveling to a strange city. Take some precautions,'' Lipcon said. You wouldn't walk alone at night in a strange city; don't do it on a cruise ship. You wouldn't go to a stranger's room ashore; don't go to a crew member's room on board.</p><p>Those are some of the safety tips that Lipcon gives in his book.</p><p>''That's the reason I wrote the book -- [to tell passengers] how to avoid problems,'' said the Miami attorney, who has filed many lawsuits on behalf of clients who experienced problems aboard ship.</p><p>''When you get on a cruise ship, you're not in the United States any more,'' he warned. The laws of the ship's country of registry aren't the same as those in America, and you may not get the protections. Medical care is limited and may not be up to U.S. standards.</p><p>Passengers having too good a time at a ship bar also may be at risk, Lipcon writes. ''Fueled by firewater, people do crazy things.'' Young women in particular can fall prey to the date rape drug. His advice to them: Only drink beverages you have witnessed being prepared, and ask that bottled drinks come unopened. ``That's a must.''</p><p>Stateroom safety is another area Lipcon touches on. ''Never open your door to strangers,'' he writes. All valuables should be locked in a safe and guard your key card, just as you would your credit card ashore.</p><p>That said, the vast majority of passengers never experience any problems aboard, except perhaps for spending more than they intended.</p><p>Cruise line representatives say crimes on board are extremely rare. Quoting from testimony at last year's Congressional hearings, Michael Crye, executive vice president of the Cruise Line Industry Association, said that of the 4.4 million passengers who sailed from April to Aug. 24 in 2007, only .01 percent were involved in reported incidents.</p><p>While Lipcon's recitation of what can happen aboard ship can sound intimidating, the attorney says the intent of his book is not to scare people away from taking a cruise, but to send them off with their eyes open.</p><p>''Have fun, be cool, but be wary,'' he advises.</p>