We returned recently from a cruise to various cities on the Baja coast of Western Mexico. Everything went well on the beautiful ship, with great accommodations, food (no one got sick!), entertainment, casino, shore visits and all. However, boarding and unboarding the Royal Caribbean ship at the different Mexican ports was a royal pain in the butt.

Of course, tight security is necessary, but all the passport hassles requiring long lines were time-consuming and took away from the sense of freedom and enjoyment of the cruise. So, when you travel to foreign countries these days, expect the delays, but don’t make them any worse by ignoring passport requirements.

Check out passport changes put into effect in June, 2009, for American travelers. The Western Hemisphere Travel Initiative (WHTI) now requires passports for all land and sea travel outside the U.S. For cruises that leave and return to U.S. ports, passports may not be necessary, except for those passengers who take excursions from the ships in foreign ports.

Americans who travel by air must show passport books to enter or re-enter the U.S. Ship passengers may also use the passport books or cards, and/or birth certificates and photo IDs. Children under the age of 16 will also be required to show a birth certificate as proof of citizenship.

However, when you try to anticipate all possible glitches, even travel insurance may not protect you in all cases. For instance, if cruise plans are changed suddenly due to an emergency, when trying to re-enter the U.S. from a foreign port, things could get complicated.

If you’re confused about all this, welcome to the club. The simplest way to avoid any possible delays or refusals on cruises and flights, never travel outside the U.S. without a valid, in-date passport. It could also help to carry an in-date state driver’s license. If you’re traveling with young children, they should have copies of their birth certificates.

Before you leave home for travel outside the U.S., get the latest information from your neighborhood travel agency, or contact the U.S. State Department at travel.state.gov/passport/passport_1738.html