Securing safe sea routes in the Antarctic

From LinkedIn by KHOA

Second hydrographic survey completed near the King Sejong Station and an up-to-date nautical chart to be published

The Korea Hydrographic and Oceanographic Agency (KHOA) of the Ministry of Oceans and Fisheries successfully completed a second hydrographic survey at the Maxwell Bay, King George Island, Antarctica this year.

Localization with the GeoGarage platform (UKHO nautical raster chart)

Localization with the GeoGarage platform (NGA nautical raster chart)

The King Sejong Station, where the hydrographic survey was conducted, is the first Antarctic station of the Republic of Korea and various research activities have been carried out since its establishment in 1988.King George Island, where the Station is located, has recently been in the spotlight as a tourist destination thus has seen a rapid increase in maritime traffic, but as mariners have had to rely on outdated nautical charts dated between 1983 and 2006, there have been many difficulties in safe navigation and smooth research.

In response to such need, a first comprehensive hydrographic survey was conducted from 2019 to August 2020 to research the bathymetry, coastline and others near the King Sejong Station. Consecutively, KHOA carried out a second high-resolution survey in January this year for 15 days onboard RV Araon.

 

The second survey found that the depths ranged from 0.46m to 400m and the seafloor mostly consisted of mudflats containing gravel.

In addition, we discovered traces of glacier caused by massive floating ice trapped on the seafloor, as well as waterways and a fjord created by the melting and erosion of glaciers.

 

 

On this survey a new undersea feature at 400m in height was also found 274km north-northwest from the King Sejong Station and a naming proposal in Korean will be submitted for international recognition.

Since the first international recognition of Anyongbok Seamount and Ulleung Plateau and eight others in 2007, we have listed so far a total of 61 undersea features in Korean around the world.

 

KHOA is currently producing a nautical chart with a scale of 1:10,000 using the acquired bathymetric data.

As soon as it is finished, it will be released in May through our Polar Navigational Safety Service at https://khoa.go.kr/polar to support the safety of vessels navigating in the Antarctic.

 

“We hope to support research activities and navigational safety in the Antarctic through the up-to-date nautical chart,” said Dr Lae Hyung Hong, Director General of KHOA. 

“KHOA plans to conduct a third hydrographic survey at the end of the year to supplement the data from the first and second surveys with more accuracy.”

Essential knots: how to tie the 20 knots you need to know

From Popular Science by Tim MacWelch

One of these knots could save your life one day.

 

Knot tying has always been one of those key outdoor skills that the inexperienced take for granted. 

The experienced outdoorsman, however, has had enough success and failure to know that there are right and wrong knots for certain jobs.

But first, it helps to know a few strange terms.
Put it simply, a knot is some kind of fastening or splice made by intertwining one or more ropes or some other flexible material.
After tightening a knot, it should hold on its own.
A hitch is a little bit different.
It’s like a knot, but it generally involves another object like a stick, a post, a ring, or occasionally another rope.
Properly tied, hitches can hold their place, or they may be able to slide, depending on the hitch you choose.
A lashing is like a hitch, but slightly more complex.
Lashings involve the use of a rope or similar material to secure two or more objects together.
To grossly oversimplify all this, the knot is just rope fastened together; the hitch is a rope fastened to an object; and a lashing is a rope fastening multiple objects together.

A good knot can save lives when you’re dealing with a survival situation, performing first aid, and when working over heights or water.
But, you have to know how to tie it.
So make sure you know what to do with your rope the next time you head into the wild by learning these 20 essential knots.

1. Square knot

 

 

Use a square knot to join a cut rope back together, or to create a loop of rope around something

(like a bundle of sticks).

The square knot is a classic for connecting lines and tying knots.
Whether you are tying two ropes together to make a longer rope, or you are tying up a bundle of firewood to carry, the square knot is a winner.
It’s much more secure and stable than its cousin the granny knot, which everyone is probably familiar with as part of tying their shoes.

How to tie a square knot:

You can tie a solid square knot by lapping one rope right over left, then underneath the other, and then tying the same again in the reverse direction—left over right and then underneath.
You’ll know you did it right when the working end and standing end of each rope is side by side (not making a “cross” like a granny knot).
 

2. Clove hitch

 

 

The clove hitch.

The clove hitch is an easy knot to tie, and it secures a line to a tree or post quickly, but it does slip when used alone, without any other knots as a backup.

How to tie a clove hitch:

To create a clove hitch on a tree, make a loop of rope around the tree.
Then make another loop and pass the free end of the rope under the second loop before tightening.
To tie this one over a post or stake, just create a loop in the free end of the rope and slide it over the post.
Then make another loop the same as the first.
Put the second loop over the post (just above the first loop) and tighten the hitch.

3. The bowline

 

 

My greatest mentor once told me, “When you get to the end of your rope, tie a bowline and hang on!” 

The bowline creates a loop at the end of a rope that cannot shrink or expand.
This knot is often taught and illustrated with a poem of a rabbit coming out of the hole, hopping in front of a tree, going behind the tree, and back down his original hole.

How to tie a bowline:

Form a loop on top of the long end of the line.
Pass the working end of the line up through the loop and around behind the line.
Then pass the working end down through the original loop, all while maintaining the shape of the second loop you create, which becomes your bowline loop.
Once the “rabbit” is back down its hole, pull the “tree” up to tighten the bowline.

4. The figure eight

 

Often used in climbing and sailing, the figure eight is a handy single-strand “stopper” knot that prevents rope from sliding through something like a grommet.

The figure eight knot creates a stopper wherever you need one on a rope, though the steps are also steps you take to create several other knots.

How to tie a figure eight:

To tie a figure eight, also known as a Flemish bend, simply pass the free end of a line over itself to form a loop.
Continue under and around the line, and finish the knot by passing the working end down through the original loop.

5. The sheet bend

 

 

Need to connect a fat rope to a skinny one? Do you need to connect a rope to the corner of a tarp that lacks a grommet? The sheet bend is one of the best choices to join dissimilar materials together.

The sheet bend is my favorite one of all, even though technically it’s a “bend”—a type of knot that connects one rope to another.
I like it because it’s the best bend for tying different types of material together or joining different thicknesses of rope.
This knot even joins together lines or materials that normally couldn’t be joined together because of differences in diameter.

How to tie a sheet bend:

To create a sheet bend, bend the thicker or more slippery rope into a “J” shape (like a fish hook).
Then pass the other rope through the hook shape from behind, wrap it around the entire fishhook once and then tuck the smaller line between itself and the other rope.
If the ropes are the same diameter and texture, the sheet bend actually resembles a square knot.
To tie a sheet bend with fabric or a tarp, collect, squeeze, and shape the material into a “J” shape, and then run your rope through and around the “J.”

6. Two half hitches

 

 

To secure shelter lines or hang up gear, you can tie (or untie) two half hitches in a hurry.

You can use two half hitches to secure a line to trees or poles, or to secure the line to itself like you would tying a trucker’s hitch.
A half hitch is fairly easy to tie, and I use it often to tie tarps up for shelters, or to hang up hammocks.

How to tie two half hitches:

After you wrap the rope around the standing end and through the inside of the loop created to make the first half hitch, wrap around the line the same way again to make the second half hitch.
Pull it tight and you should have two half hitches, one seated next to the other.
If you want added insurance, you can tie an overhand knot with the tag end of the line to keep the two half hitches from slipping.

7. Taut line hitch

 

Make your adjustments as needed when you slide a taut line hitch back and forth on a tightened line.

The taut line hitch takes the place of a slide to tighten or loosen a loop in a line (like a tent guy line).
This knot grips well as long as there is tension on the “taut” side of the loop.

How to tie a taut line hitch:

To tie the taut line hitch, create a loop by wrapping around a solid, unmoving object like a tree or tent stake.
With the free end of the rope, wrap around the main line twice on the inside of the loop.
Then lay the free end of the rope over the two wraps, wrap it around the main line, and draw the tag end through the loop you just created.
Cinch the wraps until tight.
Pull on the standing line and the taut line hitch should grip the loaded line.

8. Fisherman’s knot

 

 

The fisherman’s knot.

True to its name, the fisherman’s knot is pretty much only good for using with fishing line.

How to tie a fisherman’s knot:

Pass the free end of the line through or around the object to be secured, for example, through the eye of a fishhook.
Then, wrap the free end of the line around the other side of the line about five or six times.
Pass the free end of the line through the triangular opening next to the object being secured, and then pass the free end of the line through the large loop you just created by going through the small triangle.
If you are tying this one with fishing line, spit on the line before tightening to lubricate it so that the friction does not cause heat damage to the line.
Tighten the knot, trim off any extra line and enjoy your day fishing.

9. Water knot

 

Belts, straps, webbing, and other flat ribbon-like materials are notoriously tricky to connect unless you know how to tie the water knot.

The water knot safely secures webbing, flat belts, and most types of straps together.

How to tie a water knot:

To tie the water knot, start with a loose overhand knot in the end of one strap.
Pass the other strap in the opposite direction so it mirrors the route of the overhand knot on the first strap.
Take the ends of the two straps and pull the knot tight.
That’s it—it’s very simple and very strong.

10. Rolling hitch

 

 

The rolling hitch.

The rolling hitch adds a leg to an existing line.
This hitch is the basic knot behind a taut line hitch, but it can be added to any existing line.
The rolling hitch was often used historically to hook more dogs to a dog sled main line.

How to tie a rolling hitch:

Wrap the free end of one rope around the main rope to create a half hitch.
Make a second half hitch and then wrap over the entire knot to finish with a final half hitch to the other side from your starting place.

11. Prusik knot

 

 

The Prusik knot.

The Prusik knot creates a loop that can be used as an ascender or decender.
This “slide and grip” knot can also be handy for adding a loop to a rope when neither end of the rope is free.

How to tie a Prusik knot

To tie a Prusik, you’ll need a short rope and a separate long rope.
Tie a loop in the short rope that is secured with a solid knot like a square knot.
Now, wrap the loop around the long rope three times, making certain that each wrap lies flat against the long rope.
Pass the loop of short rope under itself and pull it tight.
As long as there is weight on the loop, the Prusik will grip the long rope.
You can also slide the Prusik up or down the long rope by taking the weight off the loop and pushing the wraps up or down the long rope.

12. Timber hitch

 

 

The timber hitch grabs tightly around rough, cylindrical objects like posts and logs and it’s also easy to untie when you’re done.

The timber hitch secures a rope to an object for hauling or to act as a support.

How to tie a timber hitch:

To create a timber hitch, all you need to do is run the free end of the rope around the object, like a log, that you intend to pull.
Then wrap the tag end of the rope around the inside of the loop you created four or five times.
After you tighten the timber hitch so the four or five wraps are tight against the object, the constant tension will keep the hitch seated.
 

13. Blood knot

 

 

The blood knot.

This little gem of a knot is used on fishing line to secure two lines together (mends a broken line or attaches leaders and tippets).

How to tie a blood knot:

You’ll start the blood knot by overlapping the two lines, and wrapping one free end around the other line five or six times.
Pass the free end between the two lines.
Wrap the other line the same number of times (five or six), and tuck the free end back between the two lines in the opposite direction of the other free end of the line.
If using fishing line, spit on it to reduce friction damage.

14. Man harness

 

Need a loop in a line when neither end is free?

The man harness can create strong loops in a rope or cord, which can be used for a variety of purposes.

This crafty knot allows you to put a loop in a line anywhere along the length of a rope when neither end of the line is free to tie a loop—and you didn’t hear it from me, but a man harness is great for cheating at tug of war.

How to tie a man harness:

Gather some slack in the line and make a loop so part of the line runs through the middle of the loop.
Grab the side of the loop and pull it through the gap between the line in the middle and the other side of the loop.
Pull the new loop tight, and then pull the line to cinch the man harness knot.
This knot can slip if there isn’t constant tension on the newly created loop, so keep something in the loop to hold it.
 

15. Carrick bend

 

 

The carrick bend.

This square knot alternate joins two ropes together securely, and is easier to untie than a square knot.

How to tie a carrick bend:

To tie the carrick bend, form a loop with the free end of one rope.
Pass the other rope’s free end under the first loop, and then over then under as seen in the picture.
Thread the free end across the loop passing under itself, and pull on both standing ends to tighten.
 

16. Trucker’s hitch

 

 

Tie this hitch down tightly and you’ll create a mechanical advantage that acts like a pulley.

You don’t have to be a truck driver to have a use for this rugged hitch.
The unique feature of the trucker’s hitch is it gives you a unique mechanical advantage for tightening up a line.
While tying this hitch is a little complex, it’s worth the trouble if you need to tighten lines as much as possible before securing them—I use it all the time to tie down tarps or secure shifting payloads.

How to tie a trucker’s hitch:

Start off by tying a figure eight knot with a loop of the line.
Then pass the free end of the line around or through whatever you’re attaching the rope to, before passing the line through the loop.
Next, pull the working end tight, and secure the free end with two half hitches, just below the loop.

17. Barrel hitch

 

 

The barrel hitch.

The barrel hitch has been used in sailing and construction work for centuries.
It allows you to secure a bucket, barrel or other cylindrical object to lift it in a well-balanced position.

How to tie a barrel hitch:

Place your barrel or other object to be lifted on top of your rope.
Then tie an overhand knot across the top of the barrel.
Open up the overhand knot until it wraps around the top sides of the barrel.
Tie the ends of the rope together with a square knot and then then lift.
This knot makes a fine bucket handle when the wire handle finally breaks off.

Safety warning: For safety and stability while hoisting barrels, the rope around the barrel needs to be high above the center of gravity on the barrel, but pose no danger of slipping off the top of the barrel.
FYI, beer has an excellent center of gravity.

18. Sheepshank
 

 

The sheepshank knot.

This knot seems half magic trick, half practical knot, but it shortens a line without cutting the line.
This knot keeps our long ropes in one piece, despite our miscalculations in the field.
I will use this one on bear bags, when the line is too long, but I don’t want to cut it.

How to tie a sheepshank:

To tie a sheepshank, fold the rope to the new length you need.
Create a half hitch in one end of the continuing rope, and drop it over the nearby loop.
Make a half hitch in the other standing end, drop it over its adjacent loop, and then tighten the whole thing slowly.

19.Tripod lashing

 

Three legs are sturdier than two, and the tripod is a versatile piece of camp equipment you will definitely want to learn how to build.
You can use the tripod lashing to create shelters, jerky racks, water filters, and a host of other camp fixtures.

The tripod lashing is commonly used for shelters and to support camp items, like a cooking pot over a fire.

How to tie a tripod lashing:

Start by collecting three poles that of almost identical length and thickness and lay them on the ground side-by-side.
Tie a clove hitch to one of the end poles, and then wrap around all of the poles four, five, or six times.
Now, wrap line between the poles–twice between each one–working back toward the original knot or hitch you tied.
Finish the lashing by tying the tag end of the line to the tag end of your original knot.
Spread the legs of the tripod and use it in your camp for something handy.

20. Square lashing

 

 

The square lashing.

The square lashing has been used to build everything from camp chairs to towers and bridges – but you can also use it to secure two poles together.

How to tie a square lashing:

Tie a clove hitch to one of the poles, near the place where the two poles cross.

Then wrap your line around the junction of the two poles, going under the lower pole and over the top pole.
Spiral outward with these wraps five or six times.
Next, wrap between the poles, biting onto the previous wrappings to tighten them.
Finally, use a square snot to tie the free end of the rope to the free end from the clove hitch that started this whole lashing.
Easy, right?

 

Links :

• DiscoverBoating : 5 Basic Boating Knots for Beginners

Solving Longitude: Jupiter's Moons

Corrected map of France: showing the coastline of France after scientifically mapping it in the late 17th century
This map compares France’s coastline mapped using Jupiter’s moons with those previously drawn. It is said the French king complained that the astronomers had taken more territory from him than his enemies.
Corrected on the order of the King, according to the observations of the Master of the Academy of Sciences

This is how Louis XIV would have declared that his geographers had made him lose more territories than all his enemies ...

From RMG

There were many proposed solutions to the Longitude problem, as discussed in Ships, Clocks & Stars.
One of the main contenders was using Jupiter's Moons as a celestial clock - though particular problems arose when attempting this at sea.

Last week, I explored how a celestial ‘clock’, the moon, could be used to find longitude at sea.
This week I want to look at another ‘celestial clock’: the four moons of Jupiter.
In the early 17th century the Italian astronomer, Galileo Galilei, made the startling discovery that several moons orbited Jupiter.
Noting that the motion of these satellites was easy to predict, Galileo suggested devices for using Jupiter’s moons for finding longitude at sea.

The method worked well on land and was being used for surveying and mapping by the late 17th century.
However, observing such small and distant objects with a telescope was very difficult from a moving ship. 

One longitude projector, Christopher Irwin, attempted to create a marine chair as a way of counteracting this difficulty.
However, when Nevil Maskelyne tested it on his voyage to St Helena in 1761, he wrote back to the Board, 'Mr Irwin's marine chair affords no convenience or advantage to an observer in using a telescope for observing the celestial phenomena but sea, but rather the contrary'.

If you get lost at sea after a shipwreck, simply balance the sector on your nose and measure the angle between the sun and the horizon. Then you'll know where you are!

From "Le grand & nouveau miroir ou flambeau de la mer" 

 

By the early 1800s longitude-finding by timekeeper and lunar distances was proving successful and commercially viable.However, the search for other methods went on and the Board considered proposals for finding longitude from Jupiter's satellites right through to its demise in 1828.

One such proposal came from Samuel Parlour, who wrote to the Board in 1824 from the East India Military Seminary in Surrey, enclosing his sketch and description of a device incorporating a telescope with a magnifying power of 80 times.

Having tested it at sea between London and Lyme Regis, Parlour believed that it would be steady enough for observing Jupiter’s satellites or the conjunction of the Moon with other stars, ‘even in a rough sea, and heavy swell’.
These were grand claims, but the Board took Parlour's ideas seriously enough to organise a sea trial the following year.

Sadly, the resulting report found that the apparatus was too difficult to manage.

 Celatone by Matthew Dockrey

 

Despite the ultimate failure of Parlour’s proposal, his design has continued to inspire.

It was the inspiration for Longitude Punk’d competition winner, Celatone by Matthew Dockrey

 

Links :

• GeoGarage blog : Longitude - The story of a lone genius who ...  / Navigating 18th-century science: Board of ...  / Lines of Longitude explained, with maps / Longitude by wire / Opinion: How the Prime Meridian changed ... 
  

Robotic navigation tech will explore the Deep Ocean

The Orpheus submersible robot is being developed by Woods Hole Oceanographic Institute and JPL to explore the deep ocean autonomously.

Orpheus uses vision-based navigation that works in a similar way to how the Ingenuity Mars Helicopter navigates during flight.

Credit: NASA/JPL-Caltech

From NASA

Terrain-relative navigation helped Perseverance land – and Ingenuity fly – autonomously on Mars.
Now it’s time to test a similar system while exploring another frontier.

On May 14, the National Oceanic and Atmospheric Administration (NOAA) ship Okeanos Explorer will depart from Port Canaveral in Florida on a two-week expedition led by NOAA Ocean Exploration, featuring the technology demonstration of an autonomous underwater vehicle.
Called Orpheus, this new class of submersible robot will showcase a system that will help it find its way and identify interesting scientific features on the seafloor.

Terrain-relative navigation was instrumental in helping NASA’s Mars 2020 Perseverance Mars rover make its precision touch down on the Red Planet on Feb.
18.
The system allowed the descending robot to visually map the Martian landscape, identify hazards, and then choose a safe place to land without human assistance.
In a similar way, the agency’s Ingenuity Mars Helicopter uses a vision-based navigation system to track surface features on the ground during flight in order to estimate its movements across the Martian surface.

The submersible can explore the most extreme depths of the ocean, creating 3D maps of the seafloor. Shown in this photo during a previous expedition, Orpheus is much smaller than other submersibles, making it easier to transport and operate. Credit: NASA/JPL-Caltech

Developed by engineers at NASA’s Jet Propulsion Laboratory in Southern California, an evolution of the vision-based navigation that has been used on Mars will now undergo a trial run a little closer to home: off the U.S.
East Coast in the Atlantic Ocean.

Large, high-power location-finding equipment like sonar would normally be required to navigate the dark and often murky waters near the seabed.
By utilizing a low-power system of cameras and lights, along with advanced software, Orpheus is an order of magnitude lighter than most deep-sea submersibles.
Smaller than a quad bike and weighing about 550 pounds (250 kilograms), Orpheus is designed to be nimble, easy to operate, and rugged while exploring depths inaccessible to most vehicles.

The Orpheus technology demonstration will be carried out aboard the NOAA ship Okeanos Explorer.
After departing from Florida’s Port Canaveral on May 14, the two-week expedition explores the waters off the U.S. East Coast.
Credit: Art Howard/NOAA Ocean Exploration

Designed by Woods Hole Oceanographic Institution (WHOI) in collaboration with JPL, Orpheus can work untethered almost anywhere in the ocean, including the most extreme depths.
Ultimately, the project team hopes to see a swarm of these underwater robots work as a team to build 3D maps of the vast regions of unexplored ocean floor in the hadal zone – regions deeper than 20,000 feet (6,000 meters).
But before the robot can explore these depths, it must first be put through its paces in shallower waters.

A readout of Orpheus’s location and depth appears on monitors in the Neil Armstrong’s computer lab. (Photo by Tim Shank, Woods Hole Oceanographic Institution) 

Diving Into the Future

“This tech demo will be used to gather data to demonstrate the viability of terrain-relative navigation in the ocean while also showing how multiple robots will operate together in extreme environments,” said Russell Smith, robotics mechanical engineer at JPL.
“These tests will put us on track to start future dives into the hadal zone and intelligently seek out exciting regions of high biological activity.”

Orpheus’ version of vision-based navigation is called visual-inertial odometry, or xVIO, and it works by using a system of advanced cameras and pattern-matching software along with instruments that can precisely measure its orientation and motion.
As Orpheus travels over the seafloor, xVIO identifies features – such as rocks, shells, and coral – below the vehicle.
Like remembering landmarks during a road trip, xVIO will construct 3D maps using these features as waypoints to help it navigate.
But this system is more than simply a means to prevent the submersible robot from getting lost.

The high-resolution maps xVIO creates are stored to memory so that when Orpheus returns to the area, it will recognize the unique distribution of the features and use them as a starting point to expand its exploration.

And when working with robot buddies, maps can be shared, cross-referenced, and developed to quickly identify areas of scientific interest.

“In the future, some of the most extreme ocean environments will be within our reach.
From deep ocean trenches to hydrothermal vents, there are many new destinations we will explore,” said Andy Klesh, a systems engineer also at JPL.

 “By staying small, we’ve created a new, simplified tool for ocean scientists – one that directly benefits NASA as an analogue system for autonomous space exploration.”

But Klesh noted another virtue of the collaboration between NASA and organizations like WHOI and NOAA, with their extensive oceanographic expertise: The technologies being developed to explore Earth’s oceans with smart, small, and rugged autonomous underwater vehicles could ultimately be harnessed to explore the oceans on other worlds.

Earth analogues are often used as environmental stand-ins for other locations in the solar system.
For example, Jupiter’s moon Europa possesses a subsurface ocean that could host conditions favorable to life.

“At hadal depths on Earth, the pressures are roughly equivalent to the bottom of Europa’s subsurface ocean, thought to be maybe 80 kilometers [50 miles] deep,” said Tim Shank, the biologist leading WHOI’s HADEX (Hadal Exploration) program.

 

Named for the Ancient Greek god of the Underworld, the Hadal Zone is the pitch-black part of our oceans below 6,000 meters.

Now, imagine a fleet of robots able to roam freely in the parts of the ocean that have been almost impossible for humans to reach, and bring back what they see: such as lifeforms that can survive with zero sunlight, very little nutrition, under pressure that could crush a car.

OceanX's research vessel #Alucia took engineers from Woods Hole Oceanographic Institution and NASA's Jet Propulsion Laboratory to test a brand-new prototype that will one day explore these remote, unforgiving parts of our planet, and eventually, oceans throughout our solar system.

 

“It is a profound thing to think that this expedition could be the stepping stone to new discoveries about our own planet, including answering that most fundamental question: Is life unique to Earth, or are there other places beyond this pale blue dot where life could have arisen? But before we can explore Europa or any other ocean world, we have to better understand our own home first.”

For more information about the technology demonstration, see:
https://oceanexplorer.noaa.gov/okeanos/explorations/ex2102/welcome.html

 

Links :

• WHOI : From Mars to the deep

 

Stranded in the water | Will’s story

Ex-Navy and experienced sailor Will was travelling in a tender to get to his boat when it capsized

and he fell straight into the cold water.