Suma is deemed the first pilot's manual to comprehensively describe the New World as then understood by the Spanish and Portuguese.

[4] A partial English edition, A briefe description of the weast India, was first published in London in 1578 by Henry Bynneman.

[5] Suma is deemed to consist of two parts, a cosmographical (cum nautical), and a geographical one, in that order.

[6] The cosmographical treatise expounds on the configuration and functioning of the (Ptolemaic, geocentric) universe, and further provides practical guidance on maritime navigation.

[7] The geographical discourse presents select human and physical features of the Old and (known) New Worlds, as split by the Tordesillas meridian through El Hierro.