Intriguing sets of , q even

Infinite families of ( q + 1 ) -ovoids and ( q 2 + 1 ) -tight sets of the symplectic polar space W ( 5 , q ) , q even, are constructed. The ( q + 1 ) -ovoids arise from relative hemisystems of the Hermitian surface H ( 3 , q 2 ) and from certain orbits of the Suzuki group Sz ( q ) in his projective 4-dimensional representation. The tight sets are closely related to the geometry of an ovoid of W ( 3 , q ) . Other constructions of sporadic intriguing sets are also given.