Captain Scarlett's crew seem to be sick of a gentleman by the name of Shiv-spike so they've tied him up to a giant pole and put him on the plank. But it turns out that none of the Sand Worms find him appetizing and refuse to eat him. One of the crew members, Mercer, will enlist your help in fixing this problem after you've complete the mission "A Study in Scarlett".
True Vault Hunter
From Captain Scarlett's ship, get back in your Sandskiff and head north. You'll eventually come to a small canyon that you can barely fit your sandskiff into. Make your way in a little and kill the few enemies at the front. Get out when you are forced to and you're going to have to work your way through this rather long camp. The first small area that you come to is going to have pirates but later you are going to come to some Badass enemies.
Kill these first few pirates and keep an eye on the wall to the right, you need to climb up on the ledge here to get where you are going. When you find your way onto the ledge, follow it and watch to the left side. You'll see enemies below you but from up here you have an advantage. Crouch down so you aren't such an easy target and start taking out the Corsairs and Rapscallions below. Cross the bridge over to the left and continue forward but watch to the right this time.
Further ahead, you'll see that this side is going to wrap around to the right side and come back on the other side of the canyon. You'll be attacked by some Swabbies and Rapscallions on this side so be sure to take cover. Watch the right side for some Pirates and Grogmasters. Cross the bridge when you get the chance to get to the other side and kill the Powder Monkey.
Keep working your way along this platform until you get to the last leg. Be sure to take your time here because there are quite a few enemies here including Raiders and a Badass Pirate. If you can make it to the corner, the enemies might bunch up, allowing you to grenade them.
Beyond them on the railing will be the condiments you are looking for. Grab them and hop back down. Get back to Captain Scarlett's ship and slather Shiv-spike in the condiments. When you've done so, melee him to knock him overboard.
Get back to the bounty board for your reward.