Images: Inside and outside the first boat for Kochi Water Metro delivered by the Cochin Shipyard;  Map of the  proposed  boat  service  in the Kochi region which  will  eventually cover 38 terminals.
May 18 2022: Trial runs of   new generation  hybrid ferry boats powered by electricity   with standby diesel motors are  underway  between Vytilla and Kakkanad on the Kochi  backwaters, with regular services promised from July 2022.
The Water Metro service of  Kochi Metro Rail Ltd will harness 50 seater( plus 50 standing)  air conditioned boats built at the Cochin Shipyard which recently delivered the first boat, “Muziris”, with another 23 on order for the first phase. In total the shipyards has  78  hybrid electric ferry boats on its order books.  The delivery schedule is somewht behind schedule due to Covid lockdowns; but the state government in its latest budget allocated an additional Rs  2150 crores for the Kochi Water Metro project which is likely to hasten deliveries.
 The trial  runs were conducted after the first two jetties at Vytilla and Kakkanad -- on floating pontoons -- were commissioned. Dredging has been completed on Vyttila-Kakkanad route and  is nearing completion on the  High Court-Vyttila route
Construction of  a terminal at Eloor has been completed  while those  for  Vypeen, Bolgatty, High Court, South Chittoor and Cheranalloor  are expected to be completed in June. The Kochi-centred backwaters will see 19 terminals opened in the first phase. 
Other  river metros coming
Meanwhile the Inland Waterways Authority of India under the Ministry of Ports,  Shipping and Waterways has announced plans for similar electric boat ferries in Guwahati and Dibrugarh on the Brahmaputra and at Varanasi, Kolkata and Patna on the Ganga.
These too will be 100-seaters made  by Cochin Shipyard.