No ducking out for Big 3

Kevin Garnett was still tired, his eyes dreary from a 6:30 a.m. wakeup call. Then, when he saw a Duck Boat pull up in front of Doc Rivers’ downtown apartment, Garnett must have thought he was stuck in a bizarre dream.

As a motivational exercise prior to the season, Rivers took Garnett, Paul Pierce and Ray Allen on a tour through Boston on the city’s historic amphibious vehicles. Rivers ordered his three superstars to arrive at his home at 8 a.m., and the Celtics’ coach orchestrated the same tour the Red Sox and Patriots have taken in the days following their recent championships.

Allen and Pierce picked up on Rivers’ tactic much sooner than Garnett, who had never before seen the Duck Boats and was even more horrified once they entered the Charles River.

“We were all settled and said what are we doing here?,” Garnett recalled. “Then all of a sudden, this boat basically on wheels pulls up, and [Rivers] was like, ‘This is what we’re going to do this morning.’ I was looking at him like, ‘Are you serious? This could have waited ’till the sun came out?’

“The thing went in the water. The wheels came out. We were floating. It was a boat now as much as a vehicle. It was kind of weird. I’ll be honest with you.”

Still a stranger to Boston as much as he was to a world championship, there were countless lessons learned that day for Garnett, as well as Pierce and Allen. Rivers’ message was clear: There is a route already mapped out for the Celtics in the following June, but the next several months would serve as the reservation.

“It was just like, ‘Man, to be able to do this the second time will be great because the first time was obviously with Doc,’” said Pierce, who seemed almost embarrassed he had never been on the Duck Boats during his time in Boston. “I said, ‘Next time I get on this Duck Tour, it’s going to be when we win the championship.’

“And I promised that.”