is a Japanese four-masted training barque tall ship. She was built in 1989 to replace a 1930 ship of the same name. She is overall, with a beam of and a depth of . She is assessed as . Propulsion is by two Yanmar Z280-ST diesel engines and a total of of sails. The engines have a total power of and can propel the ship at a maximum of , with a normal service maximum of . Kaiwo Maru has a range of under power. The four masts are the fore mast, main mast, mizzen mast and jigger mast. The main mast is .
Kaiwo Maru's keel was laid by Sumitomo Heavy Industries on July 8, 1988 at the Uraga shipyard, near Yokohama, Japan. She was launched on March 7, 1989, and commissioned by the former National Institute for Sea Training (NIST) on September 12, 1989. A sister ship of Nippon Maru, she is a Class-A four masted barque with a crew complement of 81 crew and 108 trainees. She is currently operated by the Japan Agency of Maritime Education and Training for Seafarer (JMETS) under the Ministry of Land, Infrastructure, Transport and Tourism (MLIT)
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. She dragged her anchor and grounded on a breakwater, receiving severe damage. Her crew of 167, mostly young cadets, was evacuated. Helicopters responded, but were unable to drop lines. So rescuers fixed ropes to the breakwater and crewmembers climbed along them. Thirty were injured, including some with broken bones. Her captain later accepted responsibility. A month later she was lifted by a floating crane and returned to Uraga shipyard. The ship sailed again in January 2006 after major repairs.
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, holding the speed record for 26 years from 1990 to 2016. In 2010, Kaiwo Maru visited San Francisco, California to commemorate the 1860 voyage of the Kanrin Maru, the first Japanese ship to officially visit the United States. 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.
In March 2011, Kaiwo Maru was on a voyage from Japan to Honolulu, Hawaii when an earthquake and tsunami struck Japan. She was subsequently diverted to à Âkuma, Fukushima where she served as accommodation for workers tackling the nuclear crisis at the Fukushima I Nuclear Power Plant.