Definition of expert: A man with a briefcase more than 25 miles from home. That's me.

When Katherine and Joe Satrom asked me to serve as the historian for a 15-day cruise between San Diego and Fort Lauderdale by way of the Panama Canal, I jumped at the chance.

I leapt, I hurtled, at the chance. They asked me what I knew about Central America. Immediately, the Cliff Clavin in me surfaced or perhaps it was Mr. Haney from Green Acres. We were eating brunch at a Bismarck hotel. "Costa Rica," I said in my most authoritative voice, " … is, er, a country … where I believe they speak something called Costa Rican (though only along the Costa) … It has an, um, economy, and of course what we might call people. Technically, we're talking here about the science of demographics, and graphics are your, er, writings, from the Greek work graphos, which gives us graphite as in your No. 2 lead pencil." Etc. Take that Miss Teen South Carolina.

In spite of this, the Satroms asked me to serve as the Theodore Roosevelt historian for the cruise. This year is Roosevelt's 150th birthday. TR did more than any other person to bring the Panama Canal into being. He regarded the building of the canal as equivalent in importance to the Louisiana Purchase (1803) and the annexation of Mexico (1845) in American history. Roosevelt visited the Canal Zone in 1906 with his wife Edith, one of the great first ladies in American history. In doing so, Roosevelt became the first American president to leave the United States during his time in office.

And then there was his "crowded hour" in Cuba on July 1, 1898. Roosevelt, as much as anyone else, turned the Caribbean into an "American lake."

Of course I wanted to go on this cruise. It was, for me, the trip of a lifetime.

So here we are, day four, anchored just opposite Mazatlan, Mexico, about to take small craft into the village for a day of sightseeing, shopping and sun. On board the ship, you find yourself talking like a junior travel agent as you discuss the next day's shore activities. You know: "A Texas Trio: Tacos, Two-Step and Hold-Um." I hope that's a card reference.

We're traveling on the Maasdam, an S-class ship (not sure what that means) of the Holland America Line. The ship has a capacity of 1,258 people. It's 720 feet long and 101 feet wide.

Our Theodore Roosevelt 150th birthday group numbers 144. It's led by the Satroms, and by Randy Hatzenbuhler and Jim Fuglie of the Theodore Roosevelt Medora Foundation. My bosses Lee and Deanna Vickers of Dickinson State University are on board, which makes me feel a little less like a truant for abandoning the frigid, windswept plains of North Dakota for the semitropical canal region. The two women in my world, my mother, 75, and my daughter, 13, are aboard. My daughter is the youngest person on the ship. Have I mentioned that I adore her?

Confession. I've never been much of a cruise ship devotee. Hearing Kathy Lee Gifford belt out the joys of the cruise experience does not exactly inspire confidence. Nor am I eager to hear Regis talk about "Glories of the Black and White Era," or see a live stage show featuring two Bradys, a Cher impersonator and the lesser Jacksons. Besides, I lived in Reno, Nev., for 15 years. That's Reno, home of the $7.95 lobster and steak dinner, and the 49-cent eggs benedict breakfast.

Food is, in fact, the weak link of cruise ship life. There is vastly too much of it, and ship patrons consume it as if they had just won a 15-day, all you can eat, pass to the Golden Corral. Generally speaking, the basic food (eggs, prime rib) is good, while the special entrees meant to signify luxury are on the whole disappointing. Because the food is "free," people eat with a frenzy and purposefulness that has nothing to do with appetite or nutrition. That's always a formula for disaster. My daughter intelligently asked where all that food winds up. I told her to imagine a 55,451-ton RV with a blue water problem of titantic proportions.

You will be glad to know that the North Dakotans (average age ca. 60) are the most polite, earnest, curious, adventuresome and even-going folks on board. The Maasdam staff already has been commenting on how perfectly pleasant North Dakotans are. The average age of the rest of the ship is around 75. I thought there would be shuffleboard, but I guess you have to be able to shuffle.

One day, I walked six miles (on strict orders) around the promenade deck of the ship. It's important to walk off one of every 10,000 calories you consume on these cruises.

As I looked out on the broad and boundless Pacific, our ship utterly swallowed up by what Homer called the "wine dark sea," I had that same feeling that comes when we look at the photograph of the Earth taken from the surface of the moon in 1969. We live on a strange, miraculous, planet that is mostly covered with water. It is astonishingly beautiful.

Although I was assured at dinner last night that global warming is the greatest hoax ever foisted upon a gullible public, I believe that anything that awakens us to the wonder of this planet, water occupying 71 percent of its surface, is a very good thing.

As I strolled along the promenade deck nibbling the rare nine-scoop ice cream cone, I saw a small school of whales breaching the surface of what Roosevelt called "a sapphire sea, wind-rippled under an almost cloudless sky."

Confession two: I'm having an absolutely dee-lightful time, and I cannot wait to pass through Mr. Roosevelt's canal.

Next week: Going through the Panama Canal.

(Clay Jenkinson is the Theodore Roosevelt scholar-in-residence at Dickinson State University. He lives in Bismarck. Contact Jenkinson at jeffysage@aol.com.}