Senkaku Bay — Vertical Granite Seascape

**Glass-bottom boat timing:** The boats depart every 30 min but only operate in calm seas (wave height <1m). Morning (8:30–10:00) typically has calmest conditions. The underwater visibility is best on sunny days when light penetrates the water — you can see 5–8 meters down to the rocky bottom and kelp forests. **Cliff trail sunset:** The observation trail faces west over the open Sea of Japan. Sunset (17:30–19:00 in summer) creates dramatic silhouette conditions as the sun sets behind the rock spires. The trail remains open after dark (no gates) — bring flashlight for return walk. **Sado geology:** The pink granite at Senkaku is geologically connected to the Kinzan gold mine (same 15-million-year-old intrusion that brought gold-bearing quartz veins). The visible granite at Senkaku is the deep plutonic root of the volcanic system that created the gold deposits 50km south.