{{Infobox ship | Ship image = File:Chegada do submarino NRP Tridente à Base Naval do Alfeite.jpg | Ship caption = NRP Tridente at the Lisbon Naval Base |module= Class overview Builders: HDWOperators: Preceded by: Albacora class submarinesBuilding: oPlanned: 3Completed: 2Cancelled: 1 |module2= |} The Tridente class, also designated as U 209PN, is a diesel-electric submarine class based on the Type 214 submarine developed by Howaldtswerke-Deutsche Werft GmbH (HDW) for the Portuguese Navy.