Tokunoshima · Japan · Cave & cavern · Reef
Senma Coast
Near-certain sea turtles among caves and crevices off a beach
Senma Coast is the main beach dive on Tokunoshima, a shore entry into calm shallows behind the reef that suits new divers. The site splits into three areas of underwater caves and crevices, with light falling through the openings. Sea turtles are close to certain here.
Also known as Senma Kaigan, Senma Beach, Senma Bay.
Where it is and how deep
27.7847° N, 128.8943° EApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
Divers enter from the beach and make a slow swim out, pushed about by the surge, before the dive proper starts at 4 m over a flat bed of rock and table coral. Inside the reef the water is calm and shallow, and there is almost no current, which makes the entry easy for newer divers.
Deeper, at around 18 m, rock structures seem to rise without end, and divers can look into the small openings, cracks and hidden corners inside the monoliths. The site is laid out in three areas with underwater caves and crevasses, where shafts of light come down through the gaps. Sea turtles are met on almost every dive.
Marine life and season
- Sea turtles
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Good | Good | Good | Good | Fair | Fair | Prime | Prime | Prime | Prime | Good | Good |
Season follows Tokunoshima: Calm seas open Tonbara from June to October, the water is warmest from July to October, May and June are the rainy season, and humpbacks come in winter.
Know before you go
- Surge pushes divers about on the slow swim out from the beach before the 4 m rock bed.
Sources
- Tokunoshima: Where Turtles Swim and Whales Sing — Savvy Tokyo
- Senma Coast dive point — DivePoint
- Tokunoshima diving tips — South West
- 千間海岸 — Redfin
- OpenStreetMap — OpenStreetMap
More dive sites in Tokunoshima
Coral garden
A giant coral head the size of a small hill
Wall
Giant trevally and dogtooth tuna on rock towers in open water
Similar dives elsewhere
Numerous sea caves cut into a geopark island
A huge cave-like arch dotted with yellow sponges and nudibranchs
Two arches, two heart-shaped openings, a dark cave below
A cross-shaped crack at 5 m, seen from the chamber below