As a general rule, tap water in the Seychelles is safe to drink, but always take care immediately after a cyclone or cyclonic storm as mains water supplies can become contaminated by dead animals and other debris washed into the system. Never drink from streams as this might put you at risk of waterborne diseases.
According to the CDC tap water is generally not safe for consumption.
According to the Numbeo water drinkability and accessibility index, tap water has a score of 52.08 / 100 (100 being best).
Numbeo considers this score to be "Moderate"
1 adult could save about 1022$ per year in Seychelles by drinking tap water instead of buying bottled water.
๐ณ Drinking tap water would also help with reducing your plastic footprint and improve environmental pollution.