The hiking trails are probably the major tourist attraction of the Cinque Terre, but especially between May and late September, there are many other activities that are as well fun and enjoyable.
Rent a kajak for example and discover in complete freedom the Cinque Terre coast, stop in a cove and a swim away from everyone. From Monterosso to Vernazza with kajak it takes only 20 minutes.
In addition to chairs and umbrella at the beach you can also gear up for a long swim or snorkel.
In the village you can also rent rafts or boats or book a private boat tour to discover the most hidden places. There is also the possibility to go fishing with expert fishermen.