Sean Carey has worked hard for seven years and it's beginning to pay off. Last winter, he qualified for the junior national swimming championships. Yet he faces what is possibly his greatest challenge: a competitor who arrived a year older and a little bit faster.

Since Steve Mortimer moved into the Carey family's home last month, Carey cannot count on automatic victories in Prince Mont League meets at University Hills as he had in the past. Last Saturday, Mortimer won the 100-meter individual medley with Carey finishing second, preventing Carey from sweeping three events. But Carey, 16, said he thinks the relationship will be a beneficial one.

"It's been a big change for me, but it won't bother me that much," said Carey, who is 6 feet 1, 165 pounds, and has a punk haircut. "It'll be good for me. When {Coach} Rick {Curl, of Curl Swim Club, Carey's year-round team} asked me if I'd mind if Steve moved in, I thought it would be good. I think it's going to work out really well."

Mortimer swam with North Baltimore Aquatics, a team that consistently produces national-caliber swimmers, until the end of the school year. He cited differences between himself and his coach as the reason for leaving, but in the Baltimore area, no other team had a comparable program. So he and his parents decided it would be best if he joined Curl. He also will attend St. John's for his senior year.

His father's job prevented Mortimer's parents from moving so Mortimer made the move alone.

"It's going to be a big change for me," said Mortimer, who is 6-4 and 170. "I think I'll be a lot more motivated this year. Some seniors go through a slump, but everything will be a new experience for me. It'll be like being a freshman all over again."

Both swimmers will travel to Orlando, Fla., for the Aug. 11-15 East Coast Junior Olympic meet. Like his newfound roommate, Mortimer qualified for his first junior national competition at 15. This spring, he qualified for the senior national championships for the first time in the 400-yard individual medley, the same event in which Carey achieved a berth for the junior nationals.

Although he professes to be the more introverted of the two, Mortimer dominated the conversation the other day after practice. Possibly because of his situation, Mortimer is more motivated and more certain of how swimming fits into his life.

"My parents don't really know what's going on in swimming," he said. "You have to set goals yourself. Sometimes it's hard to get motivated, but you have to center on you goals and what you want that season.

"School is very important. I don't think I emphasize one more than the other. Usually when I'm swimming well, I'm doing well in my school work. It's a period when I can concentrate better."

Carey said he looks to his parents as his chief source of motivation. His swimming experience parallels that of his home life. For him, being part of the team is "like being in a great big family," he said. "We're always with each other."

Now Mortimer is part of that family. "We're different," Carey said of Mortimer. "But it's not really a personality conflict. If we were the same, we really wouldn't get along so well."