1. Chao Phraya River: See the Countdown from a Cruise
For a river-level view, board The Planet Cruise at River City Bangkok Pier 3. The cruise advertises fireworks over the Chao Phraya at midnight, with a display listed from 00:00 to 00:15. On the route, you'll pass landmarks including Wat Arun, ICONSIAM, the Grand Palace, and Wat Phra Kaew. Tickets start at THB 6,900 for open-air second-floor seating; rooftop panorama and second-deck bow seats start at THB 8,900. Check in early, since the boat departs on schedule and late arrivals are treated as no-shows without a refund.