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Kashiwajima Island — Diving & Snorkeling Paradise

Published: Jun 3, 2026

Updated: Jun 3, 2026

islanddivingsnorkelingsea turtlesKuroshio Current

Kashiwajima Island — Diving & Snorkeling Paradise

Kashiwajima Island — Diving & Snorkeling Paradise 2

Kashiwajima is a small island off the coast of Tosashimizu, surrounded by some of the clearest water in Japan. The island sits in the path of the warm Kuroshio Current, which brings tropical fish, coral, and exceptional underwater visibility (often 20+ meters). Diving and snorkeling here reveal a world of butterflyfish, wrasse, sea turtles, moray eels, and seasonal schools of barracuda. The water temperature remains above 20°C even in winter, making it a year-round dive destination.

The island itself is tiny — you can walk around it in 30 minutes. There are no hotels, just a few guesthouses, dive shops, and a small fishing port. The vibe is quiet, unhurried, and focused entirely on the ocean. Most visitors come for the day, diving or snorkeling in the morning and returning to the mainland by evening.

Opening Hours

Island accessible 24 hours (bridge from mainland). Dive shops typically 8:00–17:00. Glass-bottom boat tours: 9:00–16:00 (weather permitting). Minshuku guesthouse check-in from 15:00.

Closed: Island always accessible. Dive shops and boat tours may cancel during rough seas and typhoon warnings (July–September is most unpredictable). Dive certification courses run April–October.

Entrance Fee

Island access free (bridge crossing). Guided scuba diving ¥12,000 for 2 dives (equipment included). Snorkeling gear rental ¥1,500. Glass-bottom boat tour ¥2,000 (40 min). Minshuku from ¥8,000/night with meals.

Best Season

June–October for warmest water (24–28°C) and best visibility (20+ meters). May and November are cooler but less crowded. December–March is possible for experienced divers but seas can be rough.

Visit Duration

Day trip with snorkeling and island walk: 4–5 hours. Full dive day (2 dives + lunch): 6–7 hours. Overnight stay for multi-dive experience: 2 days.

Getting There

Access Information

Kashiwajima is 20 min by car from Tosashimizu City. The island is connected to the mainland by a short bridge. Dive shops offer gear rental and guided dives (¥12,000 for 2 dives). Snorkeling gear rental ¥1,500. Best season: May–October.

Insider Guide

Premium

**Diving:** Kashiwajima has 30+ dive sites, ranging from shallow reefs (10m) to deep walls (30m). The most famous site is 'Tatsukushi' — a coral-covered reef teeming with tropical fish. Dive shops in