Casio Oceanus Manta OCW-S400

Manta is the slim premium range within Oceanus, Casio's line of analogue radio-controlled solar watches, and the OCW-S400 of March 2024 was the first Manta with a simple three-hand face. The OCW-S400-1A is the black version. Its mirror-finished dial is textured like ripples on water, and the sapphire ring on top of the bezel, printed with world-city codes, is vapour-coated in the same colour so the two read as one surface. Case and bracelet are titanium with a titanium carbide surface treatment, under a dual-curved sapphire crystal coated against reflection on both sides. It is 41.3 mm wide, 46.5 mm long and 9.2 mm thick, weighs about 79 g and is rated to 100 m. The movement charges from light, takes radio time signals from Japan, the US, Britain, Germany and China or the time from a paired phone, and runs about five months from a full charge in darkness. Casio priced it in Japan at 165,000 yen including tax.

Written 10 October 2026 from Casio Japan's press release and Impress Watch's launch report.