Day or two boat tour on Naerofjord ?

I don’t have any personal experience yet - I’m planning to be there in August (!). But I doubt that there are any 1-2 day boat tours on the Naeroyfjord. It’s too small. There are boats that go from Flam to Gudvangen, and back to Flam - just 2 hours each direction. Or you can arrange to go by boat from Flam to Gudvangen, and return to Flam by bus. See info here: https://www.norwaysbest.com/things-to-do/fjords/fjord-cruise-naeroyfjord/
Another potential option is a car ferry that goes from Kaupanger thru the Naeroyfjord to Gudvangen: https://www.fjordtours.com/things-to-do-in-norway/car-ferries/kaupanger-gudvangen/