I felt like a fish out of water aboard Harrah’s floating casino.

After blowing $15 in the slot machines, probably in less than 15 minutes, there wasn’t much to do for the rest of the two-hour cruise – except keep gambling.

Although the mystique and allure of gambling always eluded me, I was aboard Northern Star to see what a riverboat casino was like, because Joliet’s casinos are the biggest attraction along the Illinois & Michigan Canal National Heritage Corridor, which runs from Chicago to La Salle, Ill.

I didn’t lose too badly, since the average customer at one of the state’s 10 licensed casinos loses $47.44, according to Marianne Floriano, spokeswoman for the Illinois Gaming Board.

The 210-foot Northern Star is a modern “mega-yacht” that carries up to 800 customers. It offers gambling – and little else – on three casino decks that surround an atrium with a glass elevator.

The center deck is non-smoking. Less-crowded forward sections on two decks are “reserved for high-limit players.”

The casino has more than 400 slot machines and 30 gaming tables including craps, blackjack, roulette, Caribbean stud, royal match 21 and midi baccarat.

Harrah’s spokeswoman Lorraine Nelson later told me guides are available for first-time gamblers at game tables and in Harrah’s pavilion at the dock in center-city Joliet. “And if someone comes in and sits down at a table and says they never played before, our gaming hosts will take the time to teach them. Most people are less intimidated by the slot machines. Sitting down at a slot machine is pretty simple.”

Harrah’s other boat in Joliet is Southern Star II, a modern version of a 19th century riverboat, complete with decorative stacks that are lowered to fit under bridges.

Nelson said the two boats operate 22 hours a day. “Our last cruise goes out at 4:15 a.m.”The first departs at 8:30 a.m.

Not only is parking free in a four-story deck across from Harrah’s Landing, but there is no charge to board the boat. However, you do need a ticket.

“We are taxed by the number of people getting on the boats,” said Nelson. “We pay a $2-a-head tax.”The city gets $1 and another $1 goes to the state, “plus there’s a 20 percent tax on our gross gaming revenues.”

I boarded at 10 a.m. on a Friday. Nearly every employee I passed wished me good luck. The boat was not jammed, but certainly had a large crowd aboard. No age group, gender or race was predominate.

A cruise ship this is not. No swimming pool, lounge chairs or wandering servers are on the open top deck, only round tables with four chairs attached to each. I often was the only one up there. People obviously don’t board this boat just for a free sightseeing cruise.

As Northern Star pulled away from the dock, an announcer named a woman who just won $500 on one game and a man who won $450 on another. Soon another $540 jackpot was announced. Later, most announcements were about people celebrating birthdays.

Were people having fun? Occasionally I heard scattered cheers and applause. But most players wore looks of grim determination. More than a few were feeding two slot machines at once.

Northern Star went only a short distance down the Des Plaines River from the heart of Joliet to a wide basin above a dam and lock, and hung out there before heading back upstream. It’s only a two-mile cruise.

There are 10 riverboat casinos scattered around Illinois. The state, which licenses the operations, limits the number to 10. It also limits the number of slot machines and other games at each.

Floriano said the 10 casino operations had about 25 million customers last year. Their adjusted gross receipts totaled $1.2 billion.

Floriano said 20 percent of that money is taxed by the state. It also gets the $1-a-head tax, for a total of $286 million last year. It keeps 15 percent of that money, most of which goes to the state’s education assistance fund. Another share, $12 million, funds the State Gaming Board. And 5 percent, about $84 million, goes back to municipalities where the boats are located.

Has casino gambling helped Illinois? Floriano said the state still is studying the economic and tourism benefits, but added it has created about 12,000 new jobs and has helped municipalities by providing additional tax revenues.