The secrets of the feather boat, first created by noble eladrin explorers, have long since passed on to other races.
Wondrous Item 21,000 gp
Power Daily (Standard Action)
By placing this feather in water, you cause the feather to become a long swan shaped boat. This boat can hold up to five Medium or Small creatures (or two Large creatures). It can be rowed by two creatures at a speed of 4. After 12 hours, or when its user wills it (a minor action), the boat returns to its feather form.
Published in Player's Handbook, page(s) 254.