Catalysis of the reaction: (1/2)-unsubstituted naphthalenoid-(2/1)-sulfonate + 2 H+ + 2 e- + O2 = 1,2-dihydroxynaphthalene derivative + HSO3(-). Substrates include naphthalene-1,6-disulfonate (forms 1,2-dihydroxynaphthalene-6-sulfonate), naphthalene-1-sulfonate (forms 1,2-dihydroxynaphthalene), naphthalene-2,6-disulfonate (forms 1,2-dihydroxynaphthalene-6-sulfonate) and naphthalene-2-sulfonate (forms 1,2-dihydroxynaphthalene).