The Unión Marítima Formentera, a joint-stock company domiciled in Formentera and established in Ibiza by public deed passed before the notary D. José Sáez Martínez on 30 April 1925, was a shipping company of the Balearic Islands ensuring links between Formentera, Ibiza and mainland Spain — essential services for this then very isolated island. Very few companies of this period have left certificates that have survived to this day, which makes this piece particularly rare.

This registered Certificate for One Hundred Pesetas (capital paid up: one hundred pesetas), in the name of D. Vicente Marí Cardona, entered on the folio of book 1, is printed by Imprenta Mariano Tur in Ibiza. The design features two illustrated ships within a navy-blue and red border on "100 pesetas" watermarked paper. Original signatures of the chairman, the treasurer and the secretary-accountant, plus a Spanish fiscal stamp. A piece highly sought after by collectors of maritime scripophily and Balearic history.