Lochac (or Locach) was Marco Polo’s rendition of the Chinese (Cantonese) Lo-huk, which was how they referred to the southern Thai kingdom of Lavapura, or Louvo (from Sanskrit Lava, the present Lopburi “city of Lava”, after Lava, in Hindu mythology the son of Rama: Lava in Thai is spelled Lab, pronounced Lop’h; hence the name Lop’haburī, or Lop’ha-purī (Lopburi)). Louvo was united with Siam in 1350. Lopburi was a province of the Khmer empire in Marco Polo's time, and he may have used "Locach" to refer to Cambodia. The golden spires of Angkor, the capital of the Khmer empire, would have been a more likely inspiration of Marco's comment on the gold of Locach than the Lopburi of his time. As Zhou Daguan, the ambassador sent by the Yuan court to Cambodia in 1296 commented: “These [golden towers] are the monuments that have caused merchants from overseas to speak so often of ‘Zhenla [Cambodia] the rich and noble’”. The imprisonment by the Khmer ruler Jayavarman VIII of a Mongol emissary in 1281 would have been ample justification for Marco's remark on the inhumanity of its people: he said that Locach was "such a savage place that few people ever go there", and that "the king himself does not want anyone to go there or to spy out his treasure or the state of his realm". Marco also noted the abundance of elephants in Locach; Locach was notable in the Chinese annals for sending elephants as tribute.
But Paul Wheatley after G. Pauthier, who reads Soucat, and Henry Yule, in 1866, incline in favour of a location in Borneo, western Kalimantan, Sukadana or Laue ( id: Lawai) near the Kapuas River.
On Gerard Mercator's 1538 map of the world, Locat (Locach) is situated on the Indo-China peninsula to the south of Ciamba (Champa).
Beach, as a mistranscription of Locach, originated with the 1532 editions of the Novus Orbis Regionum by Simon Grynaeus and Johann Huttich, in which Marco Polo’s Locach was changed to Boëach, which was later shortened to Beach. Abraham Ortelius inscribed on his 1564 world map: Latinum exemplar habet Boeach sed male ut fere omnium: Nos italico usi fuimus (A Latin version has Boeach, but mistakenly: like almost everyone we have used the Italian).
Pentan is the island of Bintan, and Malaiur was the old Tamil name for the Sumatran city of Jambi (and is the origin of the national name Malay).
On Guillaume Le Testu’s 1556 Cosmographie Universel, Locach, under the name La Joncade, is shown as an island off a promontory of the southern continent, Terre australle, to the eastward of Grande Jaue, a northward-extending promontory of the Terre australle ( Terra Australis) to the south of Java.
The English East India Company hydrographer, Alexander Dalrymple, stated that the northern part of New Holland "seems to be what Marco-Polo calls Lochae".