Ventral scales of this snake are large, one-third to more than one-half the width of the body; the nostrils are lateral; nasal scales are separated by internasals; 19 longitudinal rows of imbricate scales are found at midbody; no azygous prefrontal shield is present; rostral scales are undivided; ventrals number 225–243; subcaudals number 38–47 in males, females have 30–35 (ventral and subcaudal counts after Smith 1943:443). The upper lip is dark brown. Total length varies with sex: males are 910 mm (36 in), females are 1,070 mm (42 in); tail lengths are similar: 110 mm (4.3 in). The 19 rows of scales and the dark brown upper lip can be used to differentiate the blue-lipped sea krait from other Laticauda species.
This species is found in the Indian and Western Pacific Oceans: Bay of Bengal (Bangladesh, East India, Andaman & Nicobar Islands, Sri Lanka, Myanmar, Thailand), coasts of Malay Peninsula to Indonesia, Timor-Leste, New Guinea, the Philippines, off the coasts of Fujian and Taiwan, Japan, Polynesia, Melanesia, Solomon Islands, New Caledonia, Palau, Vanuatu, Fiji, and Australia (Queensland). One specimen was found in Devonport, New Zealand in 2011, however it died shortly after being taken to Kelly Tarlton's Sea Life Aquarium.
