Vieques ( English pronunciation : vee-AY-kayz or - kez ) , in full Isla de Vieques , is an island-municipality of Puerto Rico in the northeastern Caribbean . Vieques ( ; viË Ë eÉ kÉ s ) , in full Isla de Vieques , is an island-municipality of Puerto Rico in the northeastern Caribbean , part of an island grouping sometimes known as the Spanish Virgin Islands .