Is the Madu River mangrove boat safari worth it or is it just a tourist trap

The mangrove tunnels themselves are genuinely beautiful: low canopies of mangrove arching over narrow waterways, kingfishers, water monitors, and on a small monastery island a working Buddhist temple. That part is absolutely worth it. The cheesy add-ons are negotiable: the "fish foot spa" is a 5-minute gimmick (tiny garra fish nibbling dead skin, harmless but cheap-feeling); the "cinnamon island" demo is short and salesy with the inevitable buy-our-products end; "monkey island" sometimes involves feeding wild macaques, which you should refuse. Book a 90 to 120 minute boat tour, agree the price upfront (around 4,000 to 6,000 LKR per boat, NOT per person), and ask the boatman to focus on the mangroves and bird-watching rather than the souvenir stops.