Glowstick

The Glowstick is a light source that can be held or be tossed a fair distance, and works underwater, but cannot be placed on a wall or floor like the Torch can (though the Sticky Glowstick will stick to surfaces they are thrown against). Glowsticks will emit light for a lengthy period of time after being thrown, and have a chance to be recoverable after 5 minutes. Glowsticks can be purchased from the Merchant for each during the Night or from the Skeleton Merchant for  during the day, if there was no full Moon. Glowsticks are also dropped by all Jellyfish, or Flying Fish and Raincoat Zombies while it's Raining, and can be found commonly in Pots and Chests.

Tips

 * The Glowstick can be used as a moving light source while mining directly downward, as it will continue to drop along with the player when the blocks underneath it are mined away.
 * Glowsticks, unlike torches, can be thrown to light an area from a distance.
 * Just like boomerangs, a Glowstick can pass through a 1 block thick wall if thrown at the right angle.
 * Since they work underwater, they can be a good, cheap substitute to torches.