Central Islip Charter School Eyes Major Expansion

CENTRAL ISLIP, NY — Inside South Shore Charter School, young students moved between classrooms where art projects lined the walls, engineering lessons asked them to test shelter models with water, and school leaders talked about building a K-12 future from the elementary grades up.

The Central Islip school opened in 2023, but school leaders say it is growing quickly, drawing families from Central Islip, Brentwood and more than 23 districts, with many coming from Central Islip and Brentwood, positioning itself as a long-term, tuition-free public charter option for local families.

“Our goal is to allow you to still know who we are,” Founder and Executive Director Dermoth Mattison said during a tour of the school. “I think it’s important that the community know that we’re here.”

South Shore Charter School currently serves 348 students in kindergarten through third grade and is preparing to add fourth grade in September, according to school officials. The school’s long-term goal is to continue expanding annually until it reaches a full K-12 model.

Mattison said the school was created in response to a need for more high-quality options for students in high-needs communities.

“I saw a need that I wanted to meet,” Mattison said. “Every parent wants what’s best for their child, and we wanted to ensure that we help their children meet the gains that we know they’re capable of making academically.”

South Shore is a public charter school, meaning it is tuition-free and publicly funded, but operates independently from a traditional school district. In New York, charter schools receive per-pupil public funding based on the students they enroll and the public school districts where those students live. At South Shore, school officials said there is no admissions exam and families apply through a lottery process when seats are available. The school is authorized by the State University of New York Charter Schools Institute.

Mattison said charter schools can give families another public-school option.

He said South Shore’s goal is not to compete with local districts, but to “complement the landscape in the community,” giving families another choice between district public schools and charter public schools.

“Our mission is to cultivate in our students the tenacity, integrity, and curiosity needed to become innovative and socially responsible leaders, ready to face and solve the ever-changing challenges facing our society,” Mattison said.

School leaders said South Shore has been recognized as a Top 1 percent school nationwide on NWEA MAP assessments each year. They also pointed to student growth on interim assessments as evidence that the school’s model is producing gains across grade levels and student groups.

In results shared with Patch, Andrea Williams, the school’s director of external affairs, said South Shore’s 2025-26 third-grade cohort achieved 99 percent proficiency on the state Grade 3 ELA assessment and 100 percent proficiency on the state Grade 3 math assessment.

The school’s approach centers on three pillars, including rigorous academics, whole child development, and community and culture.

Mattison said the school uses Project Lead the Way, a STEM-based program that introduces students to engineering concepts, design, testing, problem-solving and coding beginning in kindergarten.

“We want to develop, we want to harness innovation in our kids, where they have the foundation to be able to think about things that don’t exist yet,” Mattison said.

The school also offers robotics, debate, arts and music enrichment, and uses a co-teaching model to provide more personalized support in classrooms, school officials said.

The school’s culture is built around its “I AM GREAT” core values, which school officials say include integrity, grit, resilience, excellence, accountability and tenacity.

“We want our students to understand that there’s greatness that lies within them,” he said. “And not only our kids, but our grown-ups too.”

According to school officials, 68 percent of South Shore students are economically disadvantaged, 19 percent are English language learners and 14 percent are students with disabilities. The school serves students with IEPs, 504 plans and English language learning needs.

Mattison said at least 70 percent of South Shore families come from Central Islip and Brentwood, though the school draws from more than 23 districts.

The school has also developed partnerships with local organizations, including Pronto of Long Island, Island Harvest, LI Cares, People’s Alliance Federal Credit Union and Hope Missionary Baptist Church, according to school officials.

South Shore also has higher education partnerships with Touro University, SUNY Old Westbury and New York Institute of Technology, which school officials said help strengthen teacher recruitment, certification pathways and professional learning.

As the school grows, space remains one of its biggest challenges. Mattison said the biggest barrier to expansion is not family interest, but finding adequate facilities. Because the school is approved for Central Islip, it must remain in the community as it looks for room to grow.

“It’s never for us a question of, will families be interested?” Mattison said. “It’s about space.”

He said the school is continuing to search for partnerships and facilities that would allow it to grow.

“We have a team working hard,” Mattison said. “We’re going to move heaven and earth to make sure we’re able to actualize our goals.”

School leaders said they are focused on adding middle school grades, eventually expanding into high school and exploring future programs tied to college and career readiness. Mattison said athletics are also expected to come as students get older.

Mattison said he wants the school’s story to remain centered on students, calling South Shore “a diamond” that school leaders do not want to keep hidden.

"Our goal is to have 100 percent graduation rate,” Mattison said. “We’re going to make sure every child in our school is going to get into a college of their choice, a university, or the trades. We want everyone to know."