The two left a marina in the city of Oumihachiman on the eastern lakeside of Lake
Biwa aboard the 7.3-meter boat, which has a capacity for 10 passengers, to see a fireworks display in Otsu, police said, adding that the accident apparently occurred while they were on their way back to the marina.
Lake
Biwa in Shiga Prefecture is Japan's largest freshwater lake at 676 square kilometers and is known as the ''water jug'' of western Japan's Kinki region.
They reportedly planned to return to the same airport after flying around Lake
Biwa.
About 70% of Okishima Island's 500 residents make a living from fishing in Lake
Biwa, Japan's largest freshwater lake at 676 square kilometers.
The move comes after a large number of Lake
Biwa ayu were believed to have been killed in recent years by a bacterial disease known as ''cold water disease,'' the officials said.
The water level of Lake
Biwa in Shiga Prefecture fell to its second lowest in 80 years, registering minus 82 centimeters below the lake's standard level, they said.
The appropriately named Stout Makers FC continued their rich vein in front of goal by hammering SKW United 9-0 with Johannes Kheibeb getting six goals in the process, while
Biwa Eleven defeated Sunrise 3-0.
Hiding in the water the grebes of Lake
Biwa at year's end
While Mungara still holds the course and Australian all-comers record of 2:08:42, which he set in 2015, he will need to work hard to defend his title from Kawauchi, who is in good shape this season after his recent hit out at the Lake
Biwa Mainichi Marathon last month.
In 2010, an important discovery was made at a site called Aidani Kumahara in Shiga Prefecture, close to Lake
Biwa, 200 miles west of Tokyo: from a large house pit was recovered a tiny piece of fired clay that had been shaped into what archaeologists call a dogu, a ceramic figurine of the Jomon period.