Parents spoke out Tuesday about the controversial plan to expand of one of Miami-Dade’s premier magnet schools — the marine-themed MAST Academy.

At the school on Virginia Key, the proposal drew boos and sharp questions from MAST parents, students and alumni dressed in red.

Parent Debbie Reifenberg said expansion would ruin the school, which accepts students from throughout the county using a lottery system. “The diversity won’t be the same,” she said. “The commitment of MAST Academy students is greater than a home-school advantage.”

Later, in the chambers of the Key Biscayne Village Council, parents in white praised the plan. “We make MAST better,” said Manuel Cambó, incoming president of the PTSA for the Key Biscayne K-8 Center.

Mayor Franklin Caplan said the village could not wait for the economy, the state or bonds to improve local education. “There is a degree of self help that’s required,” he said.

Late Tuesday, the council unanimously approved the expansion plan after two hours of comment.

The School Board is to take up the $18 million proposal Wednesday.

The deal between the village and school district would:

• Upgrade the old and overcrowded K-8 Center.

• Add up to 1,100 seats at MAST Academy, with preference given to Key Biscayne residents who meet the entrance requirements.

• Add grades 6-8.

• Add recreational fields at the waterfront campus.

Proponents say the expansion proposal would give Key Biscayne residents a high school option closer to home and ease crowding at the K-8 Center, but it has angered the existing MAST community.