SAN DIEGO - Cindy Marten was unanimously named on Wednesday as superintendent of the San Diego Unified School District after serving the past decade as principal of Central Elementary School.

Martin will succeed Bill Kowba, who told the district's Board of Education Tuesday he would retire June 30 when his three-year contract ends.

"In our selection of a new superintendent we wanted an educator who is a visionary leader," board President John Lee Evans said. "We have found such a person in our own district, Cindy Martin, an educator for 25 years who started off as a teacher then became principal of one of our most challenging schools, Central Elementary, serving 850 at-risk youth, 99 percent of whom live in poverty and 85 percent of whom are English learners."

Martin called being selected as superintendent by the school board "an incredible honor."

"I believe in the hope and promise of public education in America, and I believe in doing the work to show Americans what public schools are all about," Martin said.