Because of its affinity to land, the yellow-lipped sea krait often encounters humans, but the snake is not aggressive and only attacks when feeling threatened.

The head of a yellow-lipped sea krait is black, with lateral nostrils and an undivided rostral scale.

Its upper surface is typically a shade of blueish gray, while the belly is yellowish, with wide ventral scales that stretch from a third to more than half of the width of the body.

[6] The venom is an α-neurotoxin that disrupts synapses by competing with acetylcholine for receptors on the postsynaptic membrane, similar to erabutoxins and α-bungarotoxins.

[7] In mice, lethal venom doses cause lethargy, flaccid paralysis, and convulsions in quick succession before death.

Dogs injected with lethal doses produced symptoms consistent with fatal hypertension and cyanosis observed in human sea snake bite victims.

[8] Gymnothorax moray eels taken from the Caribbean, where yellow-lipped sea kraits are not endemic, died after injection with doses as small as 0.1 mg/kg body weight, but Gymnothorax individuals taken from New Guinea, where yellow-lipped sea kraits are endemic, were able to tolerate doses as large as 75 mg/kg without severe injury.

Adult females, though, are less active on land during mating and hunt in deeper water, requiring more aquatic locomotive ability.

On dry land, a yellow-lipped sea krait can still move, but typically at only slightly more than a fifth of its swimming speed.

[12] While probing crevices with their heads, yellow-lipped sea kraits are unable to observe approaching predators and can be vulnerable.

[1] Each year during the warmer months of September through December, males gather on land and in the water around gently sloping areas at high tide.

The males then align their bodies with the female and rhythmically contract; the resulting mass of snakes can remain nearly motionless for several days.

[1] The smoked meat of a related Laticauda species, the black-banded sea krait, is used in Okinawan cuisine to make irabu-jiru (Japanese: イラブー汁, irabu soup).