Inking Seahorn (Patreon)

Wondrous item, uncommon (requires attunement)

This horn is made from a seashell. A dark metal lip and sculpted octopus hang to the open mouth of the horn. You can breathe underwater while holding the horn so long as you inhale through it.

The horn has 3 charges and regains 1d3 expended charges daily at dawn. You can use an action to expend 1 of the horn's charges to blow it, releasing a cloud of ink from it in a 15-foot cone: the nature of the ink changes depending on whether it's above or below the water.

Above Water: Each creature in the cone of ink must succeed on a DC 13 Dexterity saving throw or be blinded by the ink until the start of your next turn.

Below Water: The ink remains suspended in the cone's area until the end of your next turn or until it's dispersed by a significant current. For the duration, any creature that moves into the ink for the first time on its turn or starts its turn there must make a DC 13 Dexterity saving throw. On a failed save, the creature is blinded until the start of its next turn. Regardless, the area is considered heavily obscured.

'Don't be afraid of te dark' is te sign of a true landlubber. Anyone who's been out on open water knows better 'n 'at.