Cabin Fever

Official quest description: It's war on the high seas as Bill Teach tries to make the journey from Port Phasmatys to the pirate enclave of Mos Le'Harmless!
With his crew heading for the hills he's looking to recruit anyone eager to become a pirate to help him sink the enemy before he ends up swimming home. He's offering a lot more than a shilling to join his crew. Have you got what it takes to be a pirate?
Release date: 7 February 2006
Start: Talk to Bill Teach in the Port Phasmatys Inn.
Difficulty: *****
Length: Medium
Members only: Yes
Requirements:
Pirate's Treasure
Rum Deal
Level 42 Agility
Level 45 Crafting
Level 50 Smithing (note that a boost cannot be used)
Level 40 Ranged
Items needed: None
Monsters to kill: None. (You will be attacked by Level 57 pirates when you board the pirate ship to complete the tasks set by Bill Teach.)
Spoiler warning: Plot and/or ending details follow.
edit Walkthrough

The ship leaking in the beginning.
After speaking to Bill Teach in the inn, go to the docks and board The Adventurous, Bill Teach's ship (the most eastern one). Then talk to him to go out to sea.
An enemy pirate ship will shoot three holes in your ship. They will also destroy the cannon. The first thing you need to do is destroy their cannon so that they cannot do any more damage.
Go to the bottom level of the ship and take the tinderbox. Then take a rope from the repair locker and a fuse from the gun locker. Back on the main level, climb the central mast using the climbing net and use your rope on your sail to swing over to the enemy ship.
Make sure you have at least two spare inventory spaces each time you are 'jumping ship', If you fail your weapon and shield will end up in inventory, they will be dropped if there is no space for them.
You will be attacked by level 57 Pirates. Find the cannon, use the fuse on the gunpowder barrel, then light it to blow it up. Take the rope from the deck of the enemy's ship, climb the central mast using climbing net, attach the rope, and go back to The Adventurous.
After you talk to Bill Teach again, he will ask you to fix the holes in the hull. On the bottom floor, take 6 repair planks, 30 tacks, 3 swamp paste, and a hammer from the repair locker, since each hole takes 2 planks and 10 tacks to fix. After fixing them, use swamp paste on them to prevent leaking.
Talk to Bill Teach again. Now he will tell you to plunder the enemy ship. Take another rope from the repair locker, climb the mast, swing to the enemy ship, and climb down. Search the chest, crate, and barrel for plunder. You need to wait for them to respawn, but you can return to The Adventurous using the rope and sail after you have 10. Put it in the plunder chest. Note: If you leave the ship or get taken by a random event you will lose the plunder and have to steal it all over again.
Speak to Bill Teach. You must now shoot the enemies with the cannon. Follow these steps:

Boom!
Take a cannon barrel from the gun locker.
Use this to repair the broken cannon up on deck.
Talk to Bill again.
Take a fuse, ramrod, and a few cannon canisters from the gun locker.
Take some gunpowder from the barrel next to the cannon. Use it on the cannon.
Use the ramrod on the cannon.
Use the canister on the cannon.
Use the fuse on the cannon.
FIRE!!!! If you miss, follow step seven, then follow steps 5 - 9 again until you hit. If you hit, talk to Bill Teach.
Use the ramrod on the cannon again to clean it out.
NOTE: Remember to clean the cannon with each shot, otherwise it will explode from the previous gunpowder! If this happens, just replace the broken barrel with one from the gun locker.

Players must load the cannon with a total of three cannonballs.

Mama talks with Bill Teach.After you have shot the enemy crew, Bill will tell you to sink their ship by blasting three holes in their ship. Follow steps 5 - 9 again until you have made three hits, but use cannonballs instead of canister.
You will then be on the island Bill said you would be on. Then you will see a short cut scene involving Bill and Mama. When the cut scene is over the quest is done with. Then you can talk to Bill Teach and he will give you 10,000 coins and then he will say that he will take you here any time you wish.