Mariner Middle School

Contact Information

Principal

Fred Best

Address

16391 Harbeson Rd
Milton, DE 19968

Phone

(302) 685-8516

District

Cape Henlopen School District

Title IX Coordinator

Ned Gladfelter,

Title IX Phone

(302) 645-6686
School Website
Visit the district registration page
Mission Statement

Enrollment and Demographics

Enrollment: 547 (as of  September 30, 2025)

Enrollment by race and ethnicity
Group Percentage
White54.66%
Hispanic26.87%
Black10.24%
Multiracial6.03%
Asian1.46%
Native American0.55%
Pacific Islander0.18%

Student Characteristics

Low Income
16.27%
Students with Disabilities
14.63%
English Learners
9.87%
Homeless
1.65%

Average Class Size

Average class size distribution — 2024–25 school year

Average class size by number of students per class
Category Value
0-10 Students16
11-15 Students5
16-20 Students15
21-25 Students7
26-30 Students20
31-35 Students4
36-40 Students0
41-100 Students0

Academic Performance (2024-2025)

41.13%

English Language Arts Proficiency
Smarter Assessment (Grades 3-8) & SAT (Grade 11)

39.96%

Mathematics Proficiency
Smarter Assessment (Grades 3-8) & SAT (Grade 11)

Data Note: All data sourced from Delaware Department of Education ESSA API. Performance metrics, enrollment, and demographics are from the 2024-2025 school year. Visit the full Delaware Report Card for the most up-to-date information and the Data Dictionary for explanations of all metrics.