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: Keep travel insurance details, accommodation information and local emergency contacts accessible. For urgent medical, police or consular help, use the current official contact information rather than relying on an old travel article. 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.