noun - Channelversary is the annual recurrence of a date of one's channel swim.
He celebrated by channelversary with another marathon swim.
First known use by Gordon Gridley circa 2013.
Anniversary: Middle English anniversarie, from Medieval Latin anniversarium, from Latin, neuter of anniversarius returning annually, from annus year + versus, past participle of vertere to turn — more at annual, worth. First Known Use: 13th century