The secondary school and four primary schools were formerly five separate schools. While the smaller schools were praised by inspectors, the two larger schools on St Mary's were judged as inadequate. In response, the government forced a fresh start as a federated school, which opened in April 2002 and subsequently the other off islands bases were also federated. An inspection in June and July 2003 again found the standard of education at the St Mary's sites to be inadequate, and the school was placed in special measures until 2005. Under a succession of heads, the school has become a successful and cohesive federation, judged "outstanding" by the Office for Standards in Education in 2007. The school's GCSE results are now the highest in South West England. In 2008, the school was given funding of £13 million to build a new 3–16 school complex on a site adjacent to the existing Carn Gwaval primary school. This development took place 2010–11 and opened in time for the 2011–12 school year, which resulted in the secondary school moving permanently away from the Carn Thomas site, as well as the primary pupils at Carn Gwaval also moving into the new neighbouring school complex. The former primary school building was modernised and extended, becoming the island's main indoor sports and fitness centre.
Sites
is provided only on the most populous island of St Mary's. There, it was based at the Carn Thomas site, on the eastern edge of Hugh Town, on the road to Porth Mellon, but in 2011 relocated to a new school complex at Carn Gwaval, adjacent to an existing primary base there, between Hugh Town and Old Town. Secondary pupils from the other islands are given free board at Mundesley Hostel during the school week, returning home at the weekends and holidays. The four primary education bases are at Carn Gwaval, near Old Town — for St Mary's pupils; on Tresco, near Old Grimsby — for pupils from that island and the neighbouring island of Bryher; on St Martin's; and on St Agnes. The Carn Gwaval base has been combined since 2011 with the sole secondary education base. the main campus had 117 secondary and 111 primary pupils, and the Tresco, St Agnes, and St Martin's bases had 24, 7, and 6 students, respectively. These enrollment figures are lower than the respective England-wide averages.
Boarding facilities
The boarding facility at St. Mary's is known as the Mundesley Boarding House, accommodating year 7 onwards. the average number of boarders was 25-30. The boarding building includes the original house and the extension for boarders. The original house has the dining room, kitchen, and living roomon the ground floor and the house parents' flat on the first floor, while the extension has the boys' hostel and the clinic on the ground floor and the girls' hostel on the first floor.
