On one side of the Tsugaru Channel in northern Japan is the Sea of Japan. On the other side is the Pacific Ocean. The maximum depth of this narrow 19.5 km channel is 200 meters where the Tsugaru Current flows fastest – always moving from west to east, except when large eddies are formed.
Sarah Poplar (50, New Zealand, MSF bio here), creator of the Northland Open Water Swimming Association, took her chances on August 6th and after swimming through the ever-dynamic conditions of Tsugaru, mostly during nighttime conditions, she reached the shores of Hokkaido at 3:50 am after 9 hours 14 minutes 48 seconds. Captain Hashimoto with daughter Jessica Poplar, Ely Uemura, and Ocean Navi observer Mika Tokairin assisting on her crossing.
Oceans Seven Journey of Sarah Poplar to date
- English Channel in 14 hours 0 minutes in July 2015
- Catalina Channel in 12 hours 30 minutes in August 2018
- Cook Strait in 9 hours 45 minutes in March 2021
- Tsugaru Channel in 9 hours 14 minutes in August 2026
The Dragon of Tsugaru
Oral history of the local Japanese who live on either side of the Tsugaru Channel describe a fierce, hidden dragon that lurks beneath the black-striped, raging deep-sea currents. Local fishermen have long warned swimmers that while the surface waters may look calm, but strong, unpredictable undercurrents lurk below – the domain of a fearsome hidden dragon.
© 2026 Daily News of Open Water Swimming
“to educate, enthuse, and entertain all those who venture beyond the shoreline“
World Open Water Swimming Federation, a human-powered project
New Open Water Swimming Educational and Motivational Course – register here