Answer
Chiang Mai is an inland northern Thailand destination, so it does not have local beaches or offshore islands. For a water-focused day around Chiang Mai, compare waterfalls, hot springs, riverside areas, hotel pools and lakes; for a genuine beach trip, plan separate travel to southern or eastern Thailand.
Practical Chiang Mai planning note: Confirm current routes, fares, operating hours and pick-up arrangements before travelling. Build in extra time for traffic, weather and festival road closures, and keep the destination name or map pin available in Thai for drivers when practical. Confirm that any named venue still operates and check its present opening days, booking method and location directly. Chiang Mai is inland; beach and island experiences require travel to another region, while local water-based alternatives include rivers, lakes, waterfalls, pools and hot springs.