This is the amusing moment dolphins swim in front of a navy ship in Japan.

Footage from the 2nd Regional Coast Guard shows their discovery of Risso's dolphins from the Mabechi patrol boat near Hachinohe in Aomori on November 6.

Risso's dolphins grow to about 10ft (3m), although some specimens may reach 13ft (4m).

They are easily recognised by the heavy scarring, which appears white, on their bodies. These dolphins are found worldwide in cold to temperate waters, typically along continental shelves, due to their feeding habits.

They are listed as a 'Least Concern' species on the IUCN Red List and are included in CITES Appendix II.

The Japan Coast Guard protects Japan's coastline under the Ministry of Land, Infrastructure, Transport, and Tourism.

Founded in 1948 as the Maritime Safety Agency, it received its current name in 2000.

Its mission is to ensure security and safety at sea, with responsibilities including maritime law enforcement, national security, search and rescue, disaster response, hydrographic and oceanographic surveying, and maritime traffic management.

Although a civilian organization by law, the Japan Coast Guard has increasingly taken on quasi-military responsibilities, with significant authority in domestic and border security operations.