The captain of the San Francisco Giants — that’s captain with a capital C, crudely concocted with strips of black tape — reported for duty this season in a boat bearing precious cargo. He wore a white captain’s hat with black-and-orange trim, flung his wares starboard and set ground, at last, on a shimmering emerald green.

“He’s a complete bozo in the clubhouse,” the left-handed pitcher Alex Wood said of the captain, Brandon Belt, whose impish humor spilled onto the field on opening day. Belt emerged from the left-field corner, at Oracle Park, standing in the back of a speedboat pulled by a truck along the third-base stands. He tossed baseballs to the crowd, then hopped out, grabbed one for himself, and fired the ceremonial first pitch to Manager Gabe Kapler.

“They wanted me to catch it originally,” shortstop Brandon Crawford said. “I thought, ‘I’m not going to promote this any more than he already is.’”

Crawford is 35, one year older than Belt but about a month behind him in service time. They made their debuts in early 2011, when the Giants were the reigning World Series champions, and soon helped the team win two more titles. Now, Belt and Crawford are the old guard, guiding a Giants team that set a franchise record with 107 victories last season before losing to the Los Angeles Dodgers in a thrilling division series.

After a weekend sweep at Washington, the Giants have started this season 11-5. Refashioned as a modern contender — data-savvy, coaching-heavy, unafraid to challenge convention in their style of play — the Giants are stronger by retaining two pillars of the glory years.

“We had tons of models to look up to, and they were awesome for us,” Belt said, naming the pitchers Matt Cain and Javier Lopez and the catcher Buster Posey, who retired last fall, among his early mentors. “And I think a lot of those guys are the reasons why we won World Series back then, because we had that great leadership. Now me and Craw are able to help these young guys out and be leaders like those guys we looked up to before. And that’s fun for me.”

Belt named himself captain as a lark. Last September, when the Giants landed in Chicago for a weekend series with the Cubs, he instructed teammates to stay seated until their captain had left the plane.

“Just going for a little shock value,” he said. “They’d never heard anybody say that. I mean, it’s just so ridiculous.”

In Belt’s locker at Wrigley Field the next day, his jersey had a “C” taped to it, courtesy of his teammate Evan Longoria. Belt wore it to the dugout — again, just as a goof — but Kapler suggested he leave it on for the game. Belt homered, the Giants won, and now the taped-on “C” is a part of Belt’s legend. Some teammates wear it on a T-shirt in his honor.

“Nothing surprises me with Belter,” outfielder Steven Duggar said. “He’s unbelievable, man. The guy gets nine at-bats in spring training, comes out and lights the world on fire. And he did it last year, too. Incredible player, incredible person.”

Belt missed most of spring training with a knee injury but homered on opening day and hit .345 in the Giants’ first three series. He has thrived under Kapler and his expanded coaching staff. Entering Sunday’s game, he had slugged .584 since 2020. Only two hitters, San Diego’s Fernando Tatis Jr. and Atlanta’s Ronald Acuña Jr., had a better slugging percentage in that span with at least 500 plate appearances.

Belt, who was 2 for 5 with a triple Sunday afternoon in the Giants’ 12-3 win against the Nationals, has chased fewer pitches out of the strike zone, helping explain the surge, but said he also benefited from the coaching staff’s constant reassurance. The confidence to maintain his disciplined plate approach has helped him stay out of long slumps — and brought an end to the so-called Belt Wars, a debate among fans about his value.

“Essentially, some people in San Francisco really liked Brandon and some people were like, ‘Man, you should go out of the zone a little bit more to try to drive in that run,’” Kapler said. “But what we believe is like, this is a really, really excellent offensive profile just the way he is. So we wanted him to know that we value Brandon Belt exactly as he is, with no improvements. And I think that message freed him up a little bit.”

Kapler, who took over for Bruce Bochy in November 2019, faced a trickier issue with Crawford, who was coming off his worst season. The Giants platoon at several positions, and Crawford, who hit .228 in 2019, seemed uncertain of continuing in an everyday role.

But after playing well in the shortened 2020 season, he fully re-established himself last year, winning a Gold Glove and finishing fourth in voting for the National League Most Valuable Player Award. Crawford, who hit .298 with 24 homers, called it his best season.

“I don’t think my defense had really declined as much as maybe some sabermetrics were saying,” Crawford said, “but to get back to Gold Glove caliber defense was big, and proving people wrong always feels pretty good.”

The Giants give Crawford leeway to adjust their infield alignment — sometimes with only a glance to the bench coach, Kai Correa — if he sees something that deviates from the pregame script. But embracing new ideas is critical under Kapler and Farhan Zaidi, the team’s president of baseball operations. Crawford understands that the sport must evolve.

“It’s changed on so many levels — from celebrating on the field to how lineups and rosters are put together, through analytics and stuff like that,” he said. “But I think change, throughout the course of anything, is generally pretty good. If celebrating on the field grows the game more to maybe a younger audience, great.

“If somebody’s given a chance because their analytics were really good in the minors — and maybe in years past, they would have been overlooked because they weren’t projectable enough — that’s good for the game, too. So I think, in general, it’s good to see where the game is going.”

In some cases, though, the Giants have pushed the game forward in ways that irk their opponents. On Friday in Washington, with a six-run lead in the ninth inning, Thairo Estrada attempted to steal second base when the Nationals were not holding him on. Crawford singled on the pitch, and after Estrada was thrown out trying to score, the veteran Nationals shortstop Alcides Escobar barked at the Giants’ dugout.

“They did some things that we felt like were uncalled-for,” Nationals Manager Dave Martinez said. That echoed sentiments of the Padres the week before, when Duggar stole a base and Mauricio Dubón bunted for a single with a nine-run lead in the sixth.

Most of baseball’s unofficial code of conduct should be preserved, Belt said, for the sake of sportsmanship. But there is a difference between showboating and simply playing the game, he added — and the Giants just play.

“I get a lot of the unwritten rules, and I like the way they are,” Belt said. “But I do agree with the logic that Kap is talking about here: We’re not doing this to be disrespectful to other teams. We’re doing this to try to win games, period. And I know it doesn’t seem like that to some other guys, but we’re trying to get deeper into the bullpen, make guys throw more pitches so maybe they’re not able to use them in the next couple of days. It’s not just going out there and showing people up.”

Crawford said the Giants were actually showing more respect to their opponents by continuing to try to score. This, he said, is the message they should hear: “We can see you guys putting up some runs potentially, which could drastically change the way we approach our bullpen for the rest of the game and the rest of the series.”

It is sound logic, even if it hurts other teams’ feelings. In any case, the Giants will not apologize for the way they compete. They are thriving again, and Belt and Crawford are thrilled to ride another wave with a different crew — and a veteran (self-proclaimed) captain.

“There’s really no place I’d rather be than San Francisco,” Belt said. “I’m more passionate about the organization now than I’ve ever been.”