The Maine School for Marine Science, Technology, Transportation and Engineering is established as a public magnet school pursuant to this chapter for the purpose of providing certain high-achieving high school students with a challenging educational experience focused on marine-related science, technology, engineering and mathematics. The school is a body politic and corporate and is an instrumentality and agency of the State. The exercise by the school of the powers conferred by this chapter is the performance of an essential public function by and on behalf of the State. [PL 2015, c. 363, §4 (NEW).]