Boston — The grins spread like peanut butter on 32 eager first-grade faces when the door to Miss Tate's classroom in the McKay School in East Boston opens at 12:30 on Thursday afternoons.
Those 32 little grins are met and matched by one big grin on the face of the man who has just walked in: Petty Officer William J. Patterson of the USS Garcia.
''He's our sailor,'' explained Laura Sinclair, aged 6, with obvious pride.
And that he is. Once a week Petty Officer Patterson leaves his job as postmaster on the Garcia and becomes a school volunteer, one of about 20 sailors who have been volunteering their time in the Boston schools this year.
The program grew out of efforts to improve relations between the East Boston community and the sailors who find themselves docked there for months while their ships are overhauled in local shipyards. Since it began in February it has been drawing grins from everyone.
Getting sailors and students together has been good for public relations. And , more important, it has been good for the sailors and the students, those taking part say.
''People have really appreciated their efforts and they have done an awful lot for the kids,'' said Abigail Levy, the district coordinator for School Volunteers of Boston.
Having a sailor as a school volunteer is not like having anyone else. Unlike most volunteers, who are parents or community members, the men come from all over the country and they are young men who provide positive role models, she said.
The students look up to Petty Officer Patterson, both figuratively and literally, said Lorchelle Tate.
''He's so tall,'' said Daniel Elias, aged 7, as he rolled his eyes to where the sailor, who is 6 feet 4, was sitting in a student chair, his knees closer to his ears than to his feet. ''And I like his uniform,'' he added.
It is important for students to have people like the sailors to look up to, said Dean Yarbrough, principal of the school. ''They (the sailors) are wonderful models for the kids. Everybody knows the kids need good models. They don't get them on television . . . they don't get them from Pac-Man.''
The petty officer has been a hit with the students since the first day he came through the door, Miss Tate said. They are impressed by his uniform, which he always wears, and they are curious about his life on the ship.
''It's a special kind of thing,'' said Dominic Walker, one of her students, explaining why he likes having the sailor come to class. ''He showed us how to draw a ship.''
He provides more than the glamour of naval life, Miss Tate said. The time he spends reading with her students makes a difference. The students need the extra attention. ''I just don't have time for them all,'' she said.
The only problem she has had using a sailor to work with students is that there is not enough of him to go around, she said. They all want to bask in his attention.
''I can't use Mr. Patterson just for my slow learners,'' she said. ''The other kids get mad.''
He is as enthusiastic about working with his first-graders as they are.
''To me education is the big thing. If you can help anybody get an education, do it,'' said Petty Officer Patterson, a high school graduate with a few college courses under his belt. ''I just figured I wanted to help somehow,'' he said. ''And I like it.''
Working with children provides him with a challenge and with a change from the Navy life he has been living for the past 31/2 years, he said. ''The last 31 /2 years I seldom got to see any kids.''
Spending time with children has taught him patience, he said. ''And they seem to be so happy all the time.''
Working in the school also gives him a way to get to know Boston better, said the visitor, who is from Basalt, Colo.
His reasons for volunteering and his enthusiasm are typical of the other volunteers, said Lt. Kevin Uhrich, who serves as liaison between the ship and schools. ''They have a good time,'' he said. Volunteers come back to the ship talking about their students and say they find the work ''very satisfying,'' he said.
The Navy requires men to wear their uniforms and requires, of course, that their naval duties take priority, but there have been few conflicts, because schedules tend to be flexible while the ship is being overhauled.
The school work is the only volunteer work the Garcia's men are doing, he said.
Much of the credit for the program's success goes to Capt. Richard Monash, the Garcia commander, Abigail Levy said.
She suggested the idea to Captain Monash at a reception for the ship held by the East Boston Community Relations Committee, she said, because she is always looking for possible volunteers.
The captain has been ''more than cooperative,'' she said, supporting the program by appointing a liaison officer and allowing publicity and training on the ship.
The program is one everyone wants to see continued even after the Garcia with its 240 men leaves Boston and Petty Officer Patterson heads back to Colorado next September.
In the meantime, the Navy may be wasting his talents in the post office. A very informal survey of Miss Tate's students indicates he would make a most effective recruiter, at least among the elementary school set. Of those polled, 90 percent plan to join the Navy ''when they grow up.''