Kaiwo Maru (海王丸, Kaiō-Maru) is a Japanese four-masted training barque tall ship.

Propulsion is by two 4-cylinder diesel engines and a total of 2,760 m2 (29,700 sq ft) of sails.

[4] Her keel was laid by Sumitomo Heavy Industries on July 8, 1988 at the Uraga shipyard, near Yokohama, Japan.

On 20 Oct. 2004, Kaiwo Maru was nearly lost in Typhoon Tokage, while sheltering outside the port of Fushiki in the Bay of Toyama, Japan.

[10] Kaiwo Maru is a regular participant in international tall ship gatherings such as Operation Sail and is a multiple winner of the Boston Teapot Trophy.

[12] About 90 percent of the journey was made under sail, and they brought one passenger, a retired businessman who is descended from one of the original Kanrin Maru crew members.