This excerpt taken from the FUN 10-K filed Feb 29, 2008.
Vesting Events. A Participant shall become one hundred percent (100%) vested in his Account upon the earliest to occur of the following events:
Upon his Retirement, provided that he has at least twenty (20) Years of Service with Cedar Fair; or
Upon his death while employed by Cedar Fair; or
Upon his Disability while employed by Cedar Fair; or
Upon a Change in Control while employed by Cedar Fair.
Forfeiture of Account. Any Participant who Retires with less than twenty (20) Years of Service with Cedar Fair or who otherwise incurs a Separation from Service, other
than as a result of death or Disability, shall forfeit his entire Account.