The vallam kali — snake boat races — are the great event of the Kerala backwater year. The boats are enormous, narrow, low-prowed war canoes, paddled by crews of around a hundred men in unison to a chanted song. Kumarakom hosts its own race in August or September around the Onam festival; the nearby Nehru Trophy race at Punnamada Lake (Alappuzha) on the second Saturday of August is the most famous.
Even out of race season the boats can sometimes be seen practising in the early mornings. Several boats are kept in covered sheds along the lake shore; ask at the bird sanctuary or a homestay about visiting one. The atmosphere on race day is festival-meets-Olympics: tens of thousands of spectators on the banks, music, prayers at the temple before the race, and the boats moving at speeds that look impossible for their size.