Every morning, Derek Bond, 15, crawls out of his tiny bunk and helps five other boys clean the small room they share. Breakfast follows at a large mahogany table in the middle of the room. Then he opens his textbooks on the table, and the same room becomes his school.

Bond, of Encino, Calif., lives and learns aboard a sailing yacht.

Since September, Bond, his five classmates and their three teachers have sailed -- and held classes -- from Manchester, Mass., to Annapolis on the sleek, 64-foot "When and If," built 40 years ago for Gen. George S. Patton Jr.

They are participants in a three-year-old program called "Watermark" in which six students live for one semester aboard the yacht, used as a floating classroom by the Landmark School, a 360-student institution based near Boston in Pride Crossing, Mass., and acknowledged by experts as a leader in the field of learning disabilities.

This weekend, the yacht, which has been moored in Annapolis since Thanksgiving, will hoist its huge white sails, lift anchor and sail gracefully down the Chesapeake Bay -- with its cargo of students, teachers and a kitten named "Fletcher Christian" -- to Solomons Island, in near southern Maryland, where it will winter with all aboard.

The boys, who are engaged in intense academic study while they learn the fundamentals of seamanship by actually sailing the boat, all agree that so far the voyage -- highlighted by a lobster feast and sprinkled with bouts of seasickness -- has been exciting.

The students, whose families pay $13,000 a year to send them to Landmark, all have learning problems collectively known as dyslexia -- a neurological disorder, occurring mostly in boys, that affects a wide range of language skills, such as reading, writing, spelling and comprehension.

"In the past, children with learning disabilities were thought to be mentally retarded or emotionally disturbed," said Charles Drake, headmaster at the school and himself a victim of dyslexia. "But dyslexia is not an inability to learn, and many of the students have superior intellectual potential. We've found that if the learning environment and teaching techniques are tailored to the student's needs, we can overcome most of the effects of dyslexia."

Drake said the yacht, donated to the school by Patton's family in 1973, is ideal for learning disabled children because it forces them to live and learn under tightly structured conditions.

"The most important factor missing in the lives of many kids with learning disabilities is a sense of order and self-confidence," Drake said. "The students who spend a semester on the boat learn to be organized. They learn how to live in a structured environment and they come away from the experience with a new confidence in themselves. Our biggest goal for them is that they leave our school totally literate."

The lure of the life aboard the yacht and the careful organization required in such close quarters were evident on a recent night as the When and If, rocked by a brisk wind, creaked and tugged at its moorings.

Steve Wedlock, the skipper who doubles as a math teacher, and his crew sat in the 10-by-10 cabin, elbow-to-elbow at the boat's only table, chowing down on a dinner of boiled cabbage, ham, carrots and fresh-baked cornmeal muffins.

Moving around the table, Wedlock introduced his crew: Bond; Mark Roberts, 16, from Evansville, Ind.; Richard Lawson, 18, from Cranbury, N.J.; Peter Mark, 14, from Winnetka, Ill.; Grant Jackson, 16, of St. Catherines, Ont.; Stephen Ratkovits, 14, of Essex Junction, Vt.; Kim Pedersen, the only woman aboard, who teaches language arts; and Douglas Gale, who teaches marine science. (The three teachers also tutor two students each.)

After dinner, rather than click on a television set or turn on a loud stereo (both officially banned from the boat), the students traded jokes and sly digs, reminisced about previous ports of call and followed the antics of 8-week-old Fletcher Christian as the kitten chased a spinning penny across the table and then wobbled precariously across a curtain rope stretched in front of one bunk.

By 10 p.m., the students had completed their homework and personal projects, and it was lights out as they retired to their bunks.

They are roused from their bunks at 7 a.m. and assigned such daily chores as polishing brass, and cleaning cabin floors, bathrooms and the kitchen. After a hearty breakfast, the students settle down for four hours of classes from 8:30 to 12:30.

Regular classes cover language and arithmetic skills, with the specific needs of each student being worked out in sessions with his tutor. Twice a week, all of the students attend classes in marine science, where they study such topics as water chemistry, the structure of the earth and the components of sea water.

Once a week, the students write compositions compiled into a newsletter that tests whether they have grasped the basic language skills covered in their classes. The newsletter is duplicated and mailed to their parents.

In the most recent edition, Roberts described his Thanksgiving vacation, while Bond detailed a recent outing in which Roberts bought a leather jacket and met the group later for pizza.

Lawson wrote about the crew's required term projects and his own display of sailor's knots and splices -- a test of patience and manual dexterity -- which will be hung at the school when he returns. Mark's contribution was about his activities on Thanksgiving Day.

In the afternoons, the students leave the boat to do laundry, buy groceries, visit the local library, scout around for a gym to play basketball. Several times a week they look for a place that will permit them to take showers, which are not available aboard the When and If.

On weekends, the students and their teacher-guardians are likely to attend movies or use a school-owned station wagon to go sightseeing.

All of the students describe the voyage, which will end for the fall semester on Jan. 15, as "an exciting experience."

"We get a chance to see a lot of whales and porpoises when we're sailing," said Mark.

Bond, in his second year at Landmark, echoes the excitement: "Living on a boat is a lot of fun. I really like sailing. And the classes are good."

Landmark's Drake said the Watermark program has been a success, but that some interesting problems are beginning to develop. "Some of the kids enjoy it so much," he said, "they don't want to come back to school when the semester is over. They want to stay on the boat."