The Tsugaru Strait is a channel located between Honshu and Hokkaido in northern Japan, connecting the Sea of Japan and the Pacific Ocean.
The strait divides Japan's two largest islands, Honshu which contains Tokyo and Hokkaido, Japan's northern frontier with Russia.
The waterway is officially in international waters due to Japan's territorial waters only extending three nautical miles in this region, allegedly to allow the legal passing of nuclear-armed US ships without violating Japan's nuclear weapons ban.
The channel has both eastern and western necks, both of which extend approximately 20k across, while they have maximum depths of 200m and 140m respectively.
The Seikan Tunnel now runs under the channel at its narrowest point of 19.5k, significantly reducing transport times on ferries.
This narrowest point is also where swimmers attempt to cross this deep-water channel.
The Tsugaru Channel Swim is ranked among Asia's top 50 open water swims, and also makes up one part of the Ocean's Seven Challenge.
The Tsugaru Channel Swimming Association and the Tsugaru Strait Swimming Association govern both solo and relay swims crossing the channel.
The vast majority of water from the Sea of Japan discharges from the Tsugaru Strait, resulting in substantial currents; a key feature to take into account.
Only a handful of people have, to date, successfully crossed the channel, with David Yudovin of the US the first in 1990.
Some of the perils swimmers face, alongside the strong and unpredictable currents, are large schools of squid, jellyfish and giant tuna.
Apart from the channel's exploits as one of the Ocean's Seven Challenge, an interesting discovery was made by Thomas Blakiston, an explorer and naturalist. He discovered that animals on Hokkaido resembled northern Asian species, while those to the south on Honshu were related to southern Asian species, making it a zoogeographical line, and the channel being dubbed the 'Blakiston Line'.
When to go
It is said that the best time to attempt the crossing is during July or August.
Completing one of the daunting Ocean's Seven challenge routes and overcoming many obstacles along the way.
The difficult conditions faced by swimmers... particularly the jellyfish!
How to get there/Where to stay?
Return flights from Dublin to Tokyo presently sit at just over €700 for a trip in August this year. There is no shortage of accommodation in Honshu. Whether it be top-class five-star hotels, or more economical options, there is something to match everyone's spending capabilities and preferences.
App of the week - Virtual Runner
Have you ever wanted to experience some of the most famous running routes in the world, like the Boston Marathon, or perhaps a 10k through Central Park in New York? With Virtual Runner, you can do the next best thing.
This is a clever app that is designed for treadmill runners who are looking for some extra adventure.
All that users need to do is download specific routes onto their iPad and hook it up to a treadmill in the gym. A 'footpod' is attached to the runner's shoelace and a wireless receiver is plugged into the user's iPad.
The connector is sold separately, but the app itself is free from iTunes.