Senohama waiting area facility listing with toilets, rest space, water and showers.
Senohama Reef: an artificial-reef fish habitat off Nishiumi.
Senohama Reef: an artificial-reef fish habitat off Nishiumi.
Boat access from the Senohama waiting area makes a local operator the normal way to dive it.
Senohama Reef is a boat-access artificial reef off Nishiumi in Ainan, Japan. More than 20 sunk iron boxes rest on a sandy bottom, creating a fish habitat that rewards relaxed loops, macro photography and nudibranch hunting. The box layout makes it easy to build a simple circuit, pause for close inspection and turn the dive around without needing a long swim. It is a site for close-range reef watching rather than big depth or current, so plan it as a calm local boat outing with compact terrain and lots of fish activity.
Conservative baseline from public research. No community dives logged yet.
Depth range, seasonality, and planning context.
Reported Depth
Up to 12m
Depth Note
The listing gives a max depth of 12m and describes more than 20 iron boxes sunk on a sandy bottom.
Best Season
Year-round.
Typical Conditions
Artificial reef of sunk iron boxes on a sandy bottom, with fish concentration and macro-friendly box edges.
Site conditions, restrictions, and access requirements.
Safety Notes
Watch your buoyancy around the boxes and keep fins clear of the sandy bottom when stopping for macro.
Access Restrictions
Boat access through the Senohama waiting area is the normal route, and calm days make the boxes easier to work around.
Legal Notes
Follow the boat operator's rules at the Senohama waiting area and any local guidance.
Community notes to help plan your visit.
Scuba Diving
Good for relaxed reef loops, buoyancy practice and macro photography around the sunk box structures.
Freediving
Not a freedive target; the site is better suited to scuba loops and close-up viewing.
Snorkeling
Calm-day snorkelling may work over the shallows, but the site is mainly rewarding underwater.
Community dive logs and visit reports for this site.
Average conditions based on logged dives & visits.
Planning answers for access, conditions, timing, and site logistics.
Last Updated
Research Sources
Senohama waiting area facility listing with toilets, rest space, water and showers.
Boat-tour meeting point at the Senohama waiting area with year-round access.
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