The Difference Between Nautical Miles and Knots

The reason is ancient, and an evolution of different seafaring cultures, culminating in knots on a rope thrown to different depths over the side, as will be discussed. On land, speed is expressed in miles per hour (mph) or kilometers per hour (kph). However, measurements change when you’re at sea. You’ve probably heard the term “knot” being used to describe speed on the open sea, but what is a knot, and where did it come from?

Have you ever wondered: “Why speed at sea is measured in knots?” In this article, we’ll take a look at the history of nautical travel to provide you with the answer to this question and discuss why it is still used today.

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Early Methods Used to Measure Speed at Sea

Tales of sailors running out of basic necessities, dying of scurvy, and becoming stranded during hurricane season are commonplace in adventure stories and historical accounts of sailing vessels detained at sea.

Without knowing their speed, seafarers could run days behind schedule, endangering people on board and unsettling their loved ones waiting for them. Sailors were unable to determine their speed or distance because there were no landmarks to measure their progress on the open sea.

This is why they needed to come up with a reliable way to measure the speed of their vessels and the distance traveled. Admiralty law mandated a uniform system at some point.

The nautical mile (the equivalent of 1.1508 land-measured miles) was initially used as a unit of measurement for speed in the 15th century, and as a result, the chip log, which was the very first marine speedometer designed to measure speed, was born.

The Dutchman’s Log

Tossing a piece of wood over the vessel’s bow and timing how long it took for the stern to reach the object allowed sailors to determine how quickly their ship was traveling. This was one of the earliest forms of measurement and was the precursor for the chip log method that measured speed in knots. Dutchman’s log was the name used to describe this technique.

Chip Log Technique

By the 15th century, mariners began to use what they called the “chip log” or “common log” method to measure boat speed. This technique involved knotting a piece of rope at regular intervals. One end was attached to the ship’s stern, and the other would be attached to a pie-slice-shape piece of wood (or “chip”).

The rope, along with the wood shaped like a pie, was tossed into the sea and allowed to unroll freely as the ship advanced for a certain period, usually measured in hours (which they measured using an hourglass). After that, the number of knots that passed the ship’s stern was counted to determine how fast the vessel moved forward. The speed was expressed in knots per hour.

Where Does the Term “Knot” Come from?

Ancient mariners didn’t have access to the technology we have today. This means they had to use the materials they had on hand to measure a vessel’s speed. Once the seamen had determined the number of knots that crossed the ship’s stern using the chip log method, they used this to calculate the speed of the ship in knots per hour.

The nautical mile measures the distance from one knot to another. This is how one nautical mile per hour came to be known as a knot.

Therefore, if a ship’s speed measured 15 knots, this means that it was traveling at 15 nautical miles per hour. The day’s average of numerous readings showed to be a remarkably accurate representation of how quickly a ship was going. They used the information to navigate using dead reckoning, which was the standard practice before the development of modern technology.

Speed Measurements Today

Today, Doppler or ultrasonic sensors are used to calculate nautical speed, and the 30-second denominator has been changed to 28 in the rate calculation.

However, the term “log” still refers to the device used to gauge a ship’s speed, and nautical miles continue to be used to describe both marine and aviation distances.

The Nautical Mile Is Based on the Earth’s Circumference

Maps used in the air and sea are based on the earth’s circumference. Moreover, one nautical mile, which is about 500 feet greater than a land mile, balances out the scale variations with latitude.

The International Nautical Mile

Different nations disagreed on its measurement for several years. The international nautical mile was set at 6,076 feet in 1929, and the US accepted it in 1954. A nautical mile differs from a land mile, which is calculated based on walking distance.

Sailors and Pilots Today Still Remember the Common Log Method

Today sailors and pilots still refer to the speed of one nautical mile per hour as a knot, a remnant from the time when the crews of ships in adventure tales made do with some basic materials.

What’s the Difference Between Nautical Miles and Knots?

At this point, you may be confused about nautical miles and knots. In the section below, we’ll discuss the difference between these two terms.

Nautical Miles Measure Distance

The distance covered by water is expressed in nautical miles. As we’ve mentioned before, a nautical mile is 1.1508 land miles long, which is somewhat greater than a mile on land. Moreover, the nautical mile is based on latitude and longitude, and a nautical mile is equivalent to one minute of latitude.

Knots Measure Speed

On the other hand, the term knot is utilized to denote speed. One nautical mile per hour, or about 1.15 land miles per hour, is equal to one knot.

Final Thoughts

Ancient mariners used whatever they had to measure nautical speed, and their innovative techniques have shaped maritime measurements today. Next time you hear the word “knot” being used at sea, you’ll know what it means and how it came to be a monumental measurement.

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One way to win is not to get bitten by using cover and concealment. But that’s not always possible. And some sharks throw a seal around to stun the seal before they eat them. So is fighting an option? Below, top Los Angeles boat accident attorney Michael Ehline goes over the essential details fishermen and tourists on cruise ships must know to avoid death by shark attack. He has spent extensive time interviewing researchers and examining case studies involving SeaDoos, small boats and surfers. Ultimately, we will review some survival tips to fight off a shark attack at sea.

Let’s put our eyes on a case involving Charles Gregory, aged 25. In a riveting tale of survival, one man’s struggle against a shark attack at sea reached a dramatic conclusion. The search for a missing boater by boat and helicopter reached its zenith as the U.S. Coast Guard located him adrift. It was adrift, approximately 12 miles off the shores of St. Augustine, Florida. His vessel, mostly submerged, bore witness to his ordeal.

Gregory was rescued on Saturday, August 5th, almost 48 hours after he had embarked from the Lighthouse Park Boat Ramp Thursday, August 3rd. His disappearance was officially reported on the subsequent Friday by the U.S. Coast Guard. Amidst the expanse of the ocean, an HC-130 Hercules airplane’s crew sighted Gregory on a Saturday morning, seated within his partially submerged Jon boat, as disclosed by the Coast Guard’s news release.

The boat’s bow dipping beneath the water’s surface was evident from U.S. Coast Guard footage. Upon reaching the shore, Gregory was transported via stretcher to an awaiting ambulance, revealing signs of significant sunburn. His legs had weakened due to muscle atrophy, an aftereffect disclosed in an August 5th Facebook post by The Surf Station, where Gregory worked as an employee. The shop acknowledged his challenges, including the presence of circling sharks around his beleaguered vessel.

The origin of this harrowing tale traces back to the early hours of the morning two days prior. Charles had ventured out into the inlet on his modest boat, a routine he had undertaken countless times to pursue bull reds, a type of fish. However, a sudden rogue wave capsized his craft forcing him overboard in the water alongside the craft. Eventually he took turns going aboard the partially sunken vessel as temporary refuge on the boat to escape encircling marine mammals and fish. The fisherman was repeatedly stung by jellyfish as he spotted multiple sharks as he battled the sweltering heat. In the shocking video on Twitter, FLIR shows the fisherman’s harrowing last moments on the chilly waters before police authorities rescued him.

Risk Gregory Faced of Tiger Shark and Other Attacks

• Hammerhead sharks: The top predators among many other sharks.
• Mako sharks: They weigh between 150 and 200 kilograms.
• Shortfin mako: This species was responsible for at least nine attacks on humans between 1980 and 2022.
• Oceanic whitetip shark: Among the least aggressive in the Red Sea and has rarely attacked and killed humans.
• Tiger sharks: The tiger shark remains surprisingly fast, growing up to 18 feet long among the big three species.
• Great white shark: The king of sharks and one of the big three, can be found all over the Mediterranean Sea.
• Whale Sharks: The marine mammals are tame, almost whale-like.
• Thresher Sharks: possess a heightened sensitivity to light and sound, rendering them acutely responsive to their environment. In light of this, it is advisable to refrain from making sudden, agitated movements or generating excessive noise in their presence.

Despite his desperate situation, numerous boats and planes unknowingly passed by him, failing to detect his presence amidst the vast expanse of the ocean. A testimony to the resilience of the human spirit, Charles Gregory persevered through those long hours of isolation and vulnerability.

For his family, the passage of time ushered in despair as hope dimmed. In an emotional account relayed by Gregory’s father, Raymond Gregory, a profound sense of divine intervention and the power of hope emerged.

“It’s a miracle. There is a God up there,” Tweeted Raymond Gregory from the station. “If you ever thought (there) wasn’t, let your kid go missing offshore in the friggin’ ocean for 38 hours. I gave up hope. I should never have given up hope.”

Amidst this narrative of survival, the account also touches on other maritime incidents and rescues, underlining the unpredictable nature of the sea and the relentless effort of those involved in safeguarding lives at sea.

How Did One Man Fight off a Shark Attack at Sea

In a chilling incident off the Oregon coast, a man swimming on a surfboard, identified as Joe Tanner, found himself in a nightmare scenario, paddling and fending off one or potentially more shark attacks; before that, he eagerly awaited a wave. The moment’s tranquility was shattered as he suddenly felt a gripping sensation on his leg. For any surfer or beach enthusiast, the situation unfolded was the stuff of nightmares.

Tanner cast his gaze downwards only to discover a formidable great white shark, its teeth bared menacingly. Incredibly, displaying remarkable courage, the 29-year-old sprang into action, countering the shark’s assault by delivering a barrage of forceful punches directly to its gills, using his fists as a weapon. This determined response compelled the predator to relent, allowing Tanner to extricate himself from the dangerous grip – a feat that has garnered awe and acclaim as nothing short of “incredible.”

Upon reaching the safety of the shore, Tanner’s resilience continued to shine. Despite his injuries, he took the reins of his first aid, guiding those around him to take a nurse’s actions. In a remarkable display of self-reliance, he instructed people to apply tourniquets to staunch blood flow from his wounds, demonstrating resourcefulness and composure in the face of adversity as he grabbed his destiny.

Marine biologists are lauding Tanner’s remarkable escape as an extraordinary feat, emphasizing that he demonstrated an impeccable sequence of actions. His responses have been deemed exemplary, from delivering forceful blows to the shark’s sensitive gills to overseeing his medical treatment until professional assistance arrived.

Background as a Nurse?

It’s worth noting that Tanner’s proficiency in first aid stems from his role as a critical care nurse at Portland’s Legacy Emanuel Medical Center. Dr. Matthew Levy, an associate professor of emergency medicine at the Johns Hopkins University School of Medicine in Baltimore, who was not directly involved in Tanner’s case, believes Tanner did it right. Dr. Levy remarked, “He’s fortunate and incredibly cool under pressure.”

Great Whites – Nasty, Fast

Differing from their counterparts, great white sharks (Carcharodon carcharias) possess the distinctive attribute of being warm-blooded. This trait endows them with the capacity to swiftly pursue their prey, according to insights provided by Lowe. Their favored targets, including marine mammals such as elephant seals, exhibit intelligence and agility that necessitates strategic approaches like ambush attacks for the great whites to secure a catch.

The precise population count of great white sharks inhabiting the West Coast remains an enigma. However, findings from a 2014 study published in the journal PLOS ONE suggested an estimation exceeding 2,000 individuals swimming along the California coastline. Despite their numerical presence, shark-human encounters remain infrequent. Nonetheless, Lowe anticipates an uptick in such occurrences as shark populations continue to expand in the forthcoming years.

Other Terrible Shark Attack

In another tragic incident, a 23-year-old Russian man named Vladimir Popov fell victim to a tiger shark attack on a beach in Hurghada, Egypt, situated along the shores of the Red Sea. In the face of imminent danger, Vladimir’s father, Yury Popov, found himself powerless to rescue his son from the relentless assault of the shark. The young man confronted an agonizing and fateful ordeal, enduring a relentless barrage from the creature for two hours.

Local individuals eventually apprehended the predator on a fishing boat. After that, the dad, Yury Popov, took matters into his own hands, courageously confronting the three-meter-long shark and ending its life in a desperate bid to avenge his son. The father, stricken with grief, recounted the tragic incident to the media, revealing the staggering brevity of the entire ordeal, condensed into a mere 20 seconds that shattered their lives.

The heart-wrenching loss of Vladimir is compounded by the fact that, in addition to him, another woman was present in the water during the attack. The distressing video of the incident captured the young man’s futile struggle against the relentless predator. Swimming near the shoreline of Dream Beach Sheraton, Vladimir was suddenly confronted by the aggressive shark. Chaos ensued as he attempted to evade the onslaught, with the shark’s fin ominously appearing nearby. Subsequent identification confirmed the victim’s identity as ‘V—Popov,’ as reported by TASS, the news agency that shared this heartrending tale.

As noted, these rare examples show the many ways a shark can threaten a person. In one case, a trained surfer with a nursing background survived. In another case, a fisherman used a partially submerged boat to stay alive. In the last example, a young Russian boy was killed by an animal. Most victims don’t survive. The below tips are expected to assist you in weathering a shark attack in this world.

Fighting off a Shark Attack

No one tip is at the top of our list. Reacting to a shark attack requires careful consideration of practical strategies and occasionally an excellent ole punch. Remember, it will happen fast and a simple fall from a gangplank could mean the end.

It is impossible to identify if it’s docile, like a whale shark.

• Stay calm and avoid panicking. Quick movements can trigger predatory behavior. Remember, sharks are often curious rather than aggressive.
• Contrary to widespread belief, attempting to deter a shark by punching its nose is not always viable.
• Fight back. Even a test bite can cause serious harm. Aim for the eyes, nose, and gills. Having a weapon like a knife can help, but target vulnerable areas. On a larger scale, orcas have utilized a ramming technique to immobilize great white sharks anywhere on Earth. It may work for you too.
• A more successful technique involves flipping smaller sharks (such as during tiger shark attacks) upside down, which can increase paralysis in these creatures.
• Maintain eye contact with the shark and show assertiveness. Stay composed and keep your eyes on the shark. Assert your presence without aggression, and avoid looking docile.
• If a shark releases its grip, swim swiftly to safety while keeping an arm wound raised above your heart to control bleeding.
• Avoid looking at your wounds, as the sight can induce shock.

Remember that sharks are powerful predators, and their injuries can be severe. Stay focused on your survival. Doctors should do their best to triage bite victims quickly, as blood loss can be deadly with these deep lacerations. If you need a lawyer after going overboard and suffering a shark attack, contact Ehline Law at (213) 596-9642 or by email.