It's a spring day. Students are in class, but they're not complaining. They're working at five learning stations, with one station examining plankton, one examining lake sediment . . .

And another steering the sailboat.

For on this day, their classroom is the Inland Seas, a 77-foot steel schooner based in Sutton's Bay, near Traverse City, Mich.

"It's a wonderful learning experience," said Barbara Lydick of Lake City Elementary School in Michigan, who has brought fifth-graders to Schoolship for the past seven years.

Tom Kelly, founder of the Inland Seas Education Association, which operates Schoolship, recently spoke with Y-Press about his "floating classroom" for people of all ages. The programs are designed for students to gain firsthand knowledge of Lake Michigan and its ecosystem. They can learn about sailing, navigation, meteorology, and fish, plankton and sediment studies.

"Our classroom is not on a street somewhere; it's out on the water. So things are constantly changing -- the weather's changing, and what you see and experience is constantly changing. And because of that, it's a real good learning place," said Kelly.

With four full-time staff members and 110 volunteers, ISEA offers classes on three schooners based at Sutton's Bay. Kelly started the nonprofit organization 12 years ago to share his love of sailing with others.

"I've been a sailor most of my life, since I was about 14. I got interested in things like aquatic biology when I was sailing. I decided to put both of those interests together and take people sailing to teach them about the environment," Kelly said.

More than 37,000 people have participated in the programs, including many middle- and high-school students. Classes are offered spring and fall for school groups and in the summer for all ages.

For school groups of 30 or less, "the whole ship is a classroom," Kelly explained. "Most of what we do is right up on deck, but we have a lab area down below where we have microscopes and stuff."

Kelly noted that middle school is ISEA's target age group. "It's kind of a pivotal time in lots of people's lives, when they're trying to figure out what they're interested in. It's also really good in high school; we just change the program slightly. So it can be good for anybody from fourth grade on up."

To prepare students for the voyage, ISEA sends a manual to each teacher a few months in advance. "It's got activities that the teacher can do to get the class ready for the trip," Kelly said.

Once the day of the trip arrives, students are involved in a variety of tasks aboard the ship. Some activities include collecting meteorological data to be sent in to the weather service, taking water, soil and fish samples, and analyzing the pH levels at the bottom of the lake.

Kelly Hall, one of Lydick's students, explained the process for collecting fish samples: "There were a couple of kids who helped lower the net down, and then we'd let it go for a few minutes and then pulled it back up to see if we caught any fish," she said. "We didn't."

But the experience is not just about academics -- students actually get a chance to sail. They help by raising the anchor, pulling the sails up, steering the ship and handling the fish net.

"It's more fun than it is learning," said student Nick Woodward.

All of these activities are covered in just four hours. In the summer, programs last two or more days, in which students carry out research projects and sometimes stay overnight on the ship. There are also adult and family programs that deal with the history of the area and trips to some of the islands in the bay.

As Kelly explained, taking 30 kids on a ship makes them very safety-conscious. "There are lifelines all the way around the boat, like a fence, and it's 39 inches high. Basically it's designed to strain out all the small people who might be wanting to go overboard," he said.

In addition, the crew performs many different kinds of drills. "But pretty much we feel that the reason we've got this great safety record on the boat is because we have one adult for about every three kids. There's a lot of supervision."

Some rules are based on common sense. "You have to sit down and you're not allowed to run and do whatever you want on the boat," student Nolan Miracle said.

In addition to having a great safety record, ISEA has been able to accommodate every student so far.

The Lake City students never ran into any problems, with the exception of one student feeling seasick.

However, Kristen Howey did have some advice for others going aboard Schoolship: "Dress warmly," she said.

But the students were unanimous in their enthusiasm for Schoolship. Kelly understands why.

"Instead of reading something out of a book or seeing a movie or being told something by a teacher, you're actually doing things. You're mentally and physically involved," he said.

For more information on Schoolship, call (231) 271 - 3077 , or look up its Web site at www. school ship . org .

ASSISTANT EDITORS: Katie Beyer, 18; Katie Glass, 14.