Naton Beach, Tumon Bay is a saltwater beach in Guam County, Guam. Across 1,006 bacteria samples collected between 2021 and 2026 at nearby monitoring stations, it earns a Beach Safety Grade of A — Excellent.
About 2% of samples at Naton Beach, Tumon Bay exceeded the EPA Beach Action Value of 104 CFU/100 mL for Enterococcus — the threshold at which water managers typically post a swimming advisory. In practice that means the safe-swimming limit was rarely crossed here over the monitored period. Bacteria samples almost never exceed the safe-swimming threshold.
In the most recent full reporting year, Naton Beach, Tumon Bay was under a swimming advisory for about 12% of its monitored beach days — a useful gauge of how often problems recur here beyond any single sample.