Earth is filled with many beautiful rivers and streams-- places where you can't help but want to take your shoes off and stick your feet in the water. Most of the time, this is a perfectly safe (not to mention satisfying) way to cool off on a hot summer day, but there's a little-known stream in England where going in any further could cost you your life.
The term "looks can be deceiving" comes to mind. You certainly wouldn't think it by looking at it, but this little stream--known as the Bolton Strid--has an insidious reputation. Locals claim it has a 100 percent mortality rate for anyone entering the stream, though there are no definitive figures on how many lives this little stream has claimed over the years.
The figure is high enough to where Bolton Abbey authorities have placed a warning sign that reads: "The Strid is dangerous and has claimed lives in the past. Please stand well back and beware slippery rocks."
Located along the River Wharfe, not too far from what remains of a 12th-century Augustinian monastery (known as Bolton Priory), this small stretch of water is just a few feet wide, compared to the Wharfe's 9 meters (30 feet). Just yards upstream, the river is both wide and shallow, but as you gradually drift toward the Strid--you would find that the river begins to narrow and deepen dramatically--Almost as if you were flipping the river completely on its side.
The waters may not look all that formidable, but many people who have tried jumping the 1.8 meters (six feet) from one side of the stream to the other and have fallen in have never been seen again.
So, what makes it so dangerous?
First of all, the stream isn't as narrow as it appears. Looks can be deceiving. It's actually highly undercut on both sides, which means the bank doesn't gradually or steeply slope, but rather, the water has eroded the ground soil to the point that there's an overhang. Not only does this pose a problem with stability, but the ground beneath is filled with all sorts of underground tunnels and caverns--where the bulk of the river's water hides. Also, if you jump and lose your footing, you wouldn't be having a good time even if you weren't potentially about to die.
All of the water rushing from the River Wharfe to the Strid is compressed as it narrows, which creates a bottleneck effect that sees the speed of the water increase dramatically and very fast. Additionally, the narrowing causes the water current to change direction--the water no longer moves horizontally, but vertically. As you can imagine, with the depth being unknown, this would pull swimmers deep beneath the surface and make it difficult to maneuver out like you normally would by pushing up with your feet in the deep end of the pool.
You would also be at the mercy of the fast currents, underwater vortices, and whirlpools. It would be impossible to swim in any direction. The currents would grab ahold of you and throw you against the hard rocks, slamming you around should you get sucked into the caverns and crevices eroded beneath the cliff face. Drowning may not be the worst thing to happen to you in the Strid--at least you'd die fairly quickly.
What lurks beneath
There are several different forces at work beneath the surface of rough waters like the Strid and similar rivers.
When two opposing currents meet, underwater whirlpools form. On a small scale, they're seen when you flush a toilet or after a long bath -- water spinning around the drain. Bigger and stronger ones that may be seen in oceans are called maelstroms. They may look harmless enough, but they can be pretty scary. Not only is it nearly impossible for a swimmer to escape their grasp, but in larger bodies of water they can even capsize small boats or kayaks.
Take the world's most powerful maelstrom. Located off the coast of Norway, this major whirlpool--called Saltstraumen--forms every six hours (or four times a day), and can reach speeds that exceed 40 kilometers (25 miles) per hour. It's formed in much the same way as the whirlpools beneath the surface of the Strid. Essentially, water currents and tides direct a lot of water through a channel that narrows to just 150 meters (490 feet) wide. High tide is when it is at its strongest, and any boats that must pass through the channel try to do so around the maelstrom's formation.
Now, any whirlpool that has a downdraft is more formally classified as a vortex. Downdraft means it can actually push objects beneath the water's surface, sometimes all the way to the body's floor. Other times it can pin a person to the side of the bank, or it can thrash one against the rocks. If you're lucky, the turbulence of being caught up will render you unconscious fairly quickly.
Perhaps the most infamous victims of the Strid were a newlywed couple, Barry and Lynn Collett, that was on a scenic hike along the River Wharfe in 1998. A storm had come through the previous night and shed a lot of rain. No one knows exactly what happened to the couple, but it's believed that at some point during their trip, the water levels began to rise very quickly, possibly by as much as five-feet in under a minute, and the couple was swept in. It took rescuers 6 days to find Lynne's body, while Barry's remains weren't discovered until almost a month later.
More recently, an eight-year-old boy was killed by the Strid when he was playing on the bank, slipped on the mossy rocks, and fell into the water on his birthday. A passerby tried to pull him from the water, but the strong currents grabbed ahold of him and pulled him under to his death.
There are many other legends surrounding deaths at the hands of the small, but mighty Bolton Strid. You can take its existence as proof that not every beautiful river is as safe as it appears to be. Always pay attention to posted warning signs and don't overestimate how well you can swim. It doesn't matter how good of a swimmer you think you are, water doesn't always behave in ways we think it should. If you plan to swim or kayak in a river, also be aware of the different types of whirlpools and how to most effectively get out of them.