Deadliest Catch

Deadliest Catch is a master quest first announced in the Guaranteed Content Poll: What’s My Name? which allowed players to vote on a name for the massive fish, Thalassus, featured in the quest.

The hunt begins
Jones, a seasoned fisherman, seeks to obtain glory by capturing Thalassus, a legendary sea monster. Jones is located outside of the bank in the Fishing Guild, hoping to find an experienced fisherman willing to aid him. After speaking with Jones, he will reveal that he needs your help to enlist a rower, obtain a sea chart of the area, and forge a giant harpoon that is capable of bringing Thalassus down. He will give you some harpoon plans.

Sea chart
Jones recommends pickpocketing the master fisher to procure the sea chart as he may not be willing to part with the chart. Successfully pickpocketing the master fisher may take a few attempts, as he may spot and stun you. The master fisher is located near the entrance of the Fishing Guild.

Giant harpoon
After successfully pickpocketing the master fisher, speak to him about finding a master smith. He mentions that Linza, a nearby smith who is working on a few projects for local fisherman, might be able to help. Be sure to speak to the Master Fisherman before searching for Linza, or she won't show up!

Linza may be found in the small town of Hemenster, located north and slightly east of the Fishing Guild. Speak to her about making a harpoon, and her interest will be piqued when you mention Thalassus. She will reminisce on her experiences with hunting cryptid creatures, namely the Crackjaw, and then agree to make a giant harpoon for you if you are able to secure one of Thalassus's teeth for her. She then hands you the Giant Harpoon.

Rower
To recruit a rower for the endeavour, head to the Tower of Life, located southeast of Ardougne. Use of the Ardougne cloak to teleport to the monastery south of Ardougne is recommended, or Fairy ring code is very close by, just head a few steps west - alternatively you can use the lodestone network.

Speak to 'The Guns', Jones's cousin who may be found lifting a log just outside of the tower. He claims that he would be more than willing to assist with the endeavour, but his seasickness prevents him from travelling out to sea. However, he mentions that his cousin usually made him a sea legs potion whenever they went fishing.

To make a sea legs potion, lowland heather must be combined with builder's tea, which is obtained from Bonafido, another builder who is located in the vicinity. There are patches of lowland heather surrounding the Tower of Life. Searching the patch that is not infected will add some heather to your inventory; trying to search any other patch will tell you that the patch is infested with aphids. After picking out an uninfected patch, ask Bonafido for some of his builder's tea. Use the tea he hands you with the lowland heather to concoct the sea legs potion for 'The Guns'.

Return to 'The Guns' and hand him the newly-brewed potion. Satisfied, he will offer to return you back to the Fishing Guild to meet with Jones.

At sea
After returning to the Fishing Guild and speaking with Jones, he will take the party out to sea. The small vessel will arrive at the wreckage, and certain wrecks must be investigated to reveal parts of Thalassus's trail. This process is identical to the method of tracking various animals in Hunter.

5 mistakes are allowed when investigating the trail. Should you investigate the wrong wreck 5 times, the trail will reset, but the correct solution will remain the same. In addition to the option to investigate the ship wrecks, various items may be looted from the wreckages.

After completing the trail to uncover Thalassus, the monster will surface, knock you and Jones overboard, and swallow Jones. After washing up onto the shore of a small island, three mermaids will mock the expedition and reveal their loyalty to Thalassus. The mermaids are rather confident and must be convinced that Jones, with his giant harpoon, poses a great danger to Thalassus now that he rests in the belly of the monster.

To diminish the confidence of the mermaids, the following dialogue options must be chosen: Choosing a different option from the ones listed above will reset the mermaids' confidence and require you to start the dialogue over.
 * 1) The Thalassus has eaten Jones the mighty fisherman.
 * 2) It should, he's been hunting for decades.
 * 3) Very horrid! After he's killed the Thalassus, he'll probably come after you.
 * 4) Trust me, I'm a great adventurer, I should know.
 * 5) Did I mention Jones has a harpoon with him?
 * 6) It's no ordinary harpoon.

Return to sea
After instilling fear into the mermaids, they will insist on tracking Thalassus down once more in order to force Jones from the beast's bowels. Upon arriving on the boat, it is necessary to track the creature a second time.

When tracking Thalassus the second time, the track uncovered is different from before, but the concept is identical. At the end of the trail, Thalassus will once again surface from the depths, and 'The Guns' will throw karambwan at the monster. Upon eating the karambwan, Thalassus will sick up and expel Jones back onto the boat. On instruction, 'The Guns' will make a break for land.

Note: There is a chance of looting an additional 3 items while hunting Thalassus for the second time.

Finishing up
Back at the Fishing Guild, Jones will reveal that he managed to snag a tooth from the beast. Head back to Hemenster and deliver the tooth to Linza. Return to the Fishing Guild one last time and talk to Jones. Quest complete.

Rewards

 * 1 quest point
 * Any loot you got from the wreckages, up to six items
 * Wieldable fishing nets (a small cast net and a big cast net) after speaking to Jones
 * The option to hunt the Thalassus 10 more times for a total of 46,660 extra experience.
 * New bank deposit boxes in the following locations:
 * Wieldable fishing nets (a small cast net and a big cast net) after speaking to Jones
 * The option to hunt the Thalassus 10 more times for a total of 46,660 extra experience.
 * New bank deposit boxes in the following locations:
 * New bank deposit boxes in the following locations:

Music Unlocked

 * Deadliest Catch - Whilst hunting the sea monster
 * Three of a Kind - On the mermaids' island

Required for completing

 * Desert Tasks:
 * Hard: "Security through Obscurity"
 * Tirannwn Tasks:
 * Medium: "Sharks Are Good for the Elf"

Salvaging Ships
Each time you hunt the Thalassus, you should aim for these items from the wreckage. You can only obtain one set of 16 Blood Runes, 5302 Coins and 17 Law Runes each hunt but you can get multiple Uncut Rubies, Green Dragonhides, and Adamantite ores.

Post-quest - Bonus Thalassus Hunts
Following the quest, players can hunt the Thalassus up to ten more times for a total of 46,660 additional Hunter experience. Doing so is a requirement for obtaining the Completionist cape. The difficulty increases with each run, adding in new challenges such as restricting the energy for 'The Guns' (and thus limiting how far you can move). If the player moves only one square at a time or toggles running then no energy will be consumed. The energy for 'The Guns' is equal to the player's run energy. The Oo'glog Salt-water spring can be used for 10–25 minutes for practically infinite energy for 'The Guns' to use.

While the path changes for each hunt, the location of the shipwrecks is fixed. The blank map may be used as an easier way to track down the Thalassus. It is recommended to mark each shipwreck which leads the player along the trail.

Trivia

 * Currently there seems to be a graphical model glitch which causes your character to have violent spasms when the fish appears during the cut-scene.
 * Deadliest Catch is also the name of a popular TV show on the Discovery Channel.
 * On the day of release, the rewards read: "Jones didn't have a strong enough line to reel in the rewards today. Pop back tomorrow when he's got himself a harpoon."
 * Upon completion of the quest the players adventurer's log will read: "I helped Jones hunt down the deadly sea creature."
 * The first part of the quest (gathering items and asking 'The Guns' to help) is a reference to .
 * Tentacle's island is a reference to the  and Greek mythology. When the mermaids 'drag' the player ashore, Tentacle addresses the player as if she were.
 * When telling Juna the story of the quest, your character says: "...and we returned to the Fishing Guild where Jones set up shop selling his Miracle Thalassus Protection Cream." at which she replies: "It's a small blessing that the creature can continue to exist."
 * The quest is a possible reference to the Biblical story of Jonah and Fish in that Jones is similar in pronunciation to Jonah and both were swallowed by a great fish (without being killed in the process).
 * It is possible to sneak Karamja rum off of the island by depositing it in the deposit box south of Brimhaven.