Smith also worked at Irvine Valley College (2004-2010), where he was the associate head baseball coach. He helped the Lasers record its most wins in program history in 2008 and earn its first postseason berth in 2005.
"We're really excited to have him take over the program, and continue to build what Jim Kiefer and Nate Goellrich had built," D'Agostino said. "He comes very well qualified and we think he's going to be a great addition to the coaches at Costa Mesa."
Kiefer was the former coach who stepped down to focus more on being the Costa Mesa boys' athletic director. Goellrich, the assistant baseball coach, became Estancia's new baseball coach earlier this month.
Smith, 39, also worked as an assistant baseball coach at Chapman University (1994-2002), where he helped lead the program to two Division III World Series appearances in 1997 and 2001.
He said he accepted the job at Costa Mesa because it's a "good baseball area," and he said the Mustangs offered a teaching position. Smith said he expects to teach physical education at Costa Mesa after the first semester break.
"I'm looking forward to working with the Jim Kiefer and Phil D'Agostino," Smith said Monday. "I feel great. I'm excited about the opportunity."
Smith said one of his assistants will be Brian Ferrante, who worked with him last season at La Quinta. Smith said he's working on bringing in other assistants as well.
"We're excited to have him," said Kiefer, who was 83-77 with four CIF Southern Section playoff appearances in his six seasons as Mesa's coach. "He comes with a good baseball background. He did a real good job at La Quinta last year. I think he's a good fit for our program. He's going to do a lot of good things with our program and move it forward."
The Mustangs, who in 2009 won the program's first league title since 1978, finished 10-15, 5-10 in the Orange Coast League last year, missing the playoffs.