Try this:
You'll notices I'm suggesting a single skill challenge that is Complexity 4 (10 success b4 5 failures). If you have 6 PCs, then that's 6 checks per round you'll be making. Requiring 10 successes should give more opportunities for all the PCs to make checks.
Ship in a Storm
The PCs are aboard an airship during a violent storm, and must secure cargo and passengers before the ship crashes!
Level 1 Skill Challenge
Complexity 4 (10 successes before 5 failures)
Primary Skills: Athletics, Endurance, Diplomacy, Intimidate, Perception,
There are two major ways that a PC can contribute to the Skill Challenge, either securing cargo or passengers:
Athletics (Moderate – DC: 20): With a successful check, the PC staves off the buffering winds and rain, and ties down cargo, secures a hatch, or otherwise keeps the ship together. A failed check costs the PC a healing surge, and a little of the cargo is blown overboard.
Endurance (Moderate – DC 20): Every round, at least one PC must attempt an Endurance check. With a successful check, the PC remains fights off the debilitating wind and rain, and serves as an inspiration to the rest of the party. A failed check costs every PC in the group a healing surge.
Diplomacy (Moderate – DC 20): With a successful check, the PC uses his or her leadership skills to convince other passengers to stay below deck, or follow the general orders of the ship’s captain. A failed check costs the PC a healing surge, and some of the passengers are swept away in the storm.
Intimidate (Easy – DC 15): With a successful check, the PC uses a commanding voice to order passengers to stay down, or for the crew to help save the ship. The PC can choose which he saves (passengers or cargo). A failed check results in the PC losing a healing surge, losing the cargo or passengers he or she was trying to save, and the Intimidate skill can no longer be used in this challenge.
Perception (Easy – DC 15): With a successful check, the PC notices looming danger before disaster strikes. A successful Perception check does not count towards the total Successes, but it does give another PC a +2 to another skill check. A failed check does not count towards the total failures, but it gives the next PC a –2 to his or her skill check, AND the first PC loses a healing surge.
Success: As long as one PC successfully saved some passengers (via Diplomacy or Intimidate), then the better part of the passengers and crew survive the crash. The group can then count on the aid of several NPC experts over the course of their future adventures (granting bonuses to skill checks, or even access to rituals). As long as one PC successfully secured some cargo (via an Athletics check), then the PCs will have access to any adventuring supplies found in the PHB, as well as one Level 2 magic item that may be discovered in the wreckage.
Failure: The airship disastrously crashes. Much of the crew and passengers are lost, and most of the useful cargo is destroyed. The PCs have access to fewer helpful NPCs, and have no access to any adventuring supplies found in the PHB. They must face the unknown with nothing but their own skills, and the gear on their backs.