Catalyzes the conversion of (2E,6E)-farnesyl diphosphate (FPP) into (2Z,6E)-hedycaryol via a 1,11-cyclization. (2E,6E)-farnesyl diphosphate + H2O = (2Z,6E)-hedycaryol + diphosphate Binds 3 Mg(2+) ions per subunit. Secondary metabolite biosynthesis; terpenoid biosynthesis. Homodimer. The Asp-Asp-Xaa-Xaa-Xaa-Glu (DDXXXE) and Asn-Xaa-Xaa-Xaa-Ser-Xaa-Xaa-Xaa-Glu (NSE) motifs are important for the catalytic activity, presumably through binding to Mg(2+). The 1,11-cyclization requires isomerization of (2E,6E)-farnesyl diphosphate (FPP) to nerolidyl diphosphate (NPP), the abstraction of the pyrophosphate from intermediate NPP leading to a (Z,E)-hedycaryl cation and finally an nucleophilic attack of a water molecule. Belongs to the terpene synthase family.