The 30-metre (98 foot) Santa Ana went down half a mile (800 metres) from Cape Peñas near Erbosa Island in Asturias after crashing into rocks, local daily El Comercio reported.
Spain's Maritime Safety Agency sent out a ship and a helicopter at 5.30am after contact with the ship was lost.
One crew member was rescued but two have been confirmed dead and six are still missing.
The crew includes five Spaniards, two Portuguese men and two Indonesians.
Spain's Atlantic coast has seen a series of wild storms this winter. In January, a freak wave killed three members of the same family who were scattering the ashes of a relative.