In Search Of A Spider

 is the third quest given by the Sea Hunter and thus the third quest in the Sea Hunter's Guild quest line.

Walkthrough
To start this quest, talk to the Sea Hunter and choose In Search Of A Spider. He will say the following:

Upon starting the quest, the Spider's Heart will have a chance to be looted off Small Spiders and Large Spiders. Simply hunt around uninhabited islands at night and kill a few until it drops, then return to any Sea Hunter to finish the quest, by choosing the same dialogue option. He will say the following once you finish the quest:

Rewards

 * Access to the Sea Hunter's Guild's third stock of items:
 * Sea Hunter's Journeyman Boots
 * Sea Hunter's Journeyman Breastplate
 * Sea Hunter's Journeyman Cape
 * Sea Hunter's Journeyman Gauntlets
 * Sea Hunter's Journeyman Greaves
 * Access to the next quest in the Sea Hunter's Guild quest line, Pursuit Of A Poacher.