Theresa Paulsen: Ship Navigation, March 28, 2015

NOAA Teacher at Sea
Theresa Paulsen
Aboard NOAA Ship Okeanos Explorer
March 16 – April 3, 2015

Mission: Caribbean Exploration (Mapping)
Geographical Area of Cruise: Puerto Rico Trench
Date: March 28, 2015

Weather Data from the Bridge: Scattered Clouds, 26˚C, Wind speed 13-18 knots, Wave height 5-7ft

Science and Technology Log

Mapping of our first priority area is now compete and we have moved to the priority two area on the north side of the Puerto Rico Trench.  We are more than 100 miles from shore at this point.  Land is nowhere in sight.  Able-Bodied Seaman Ryan Loftus tells me that even from the bridge the horizon is only 6.4 nautical miles away due to the curvature of the earth.  At this point with no frame of reference other than celestial bodies, navigation equipment becomes essential.

The ship uses Global Positioning Systems, GPS units:

Radar:

 

On the radar display, we are in the center of the circle. Our heading is the blue line. Since this photo was taken near shore, the yellow patches on the bottom indicate the land mass, Puerto Rico. The two triangles with what look like vector lines to the left of us are approaching vessels. On the right, the Automated Identification System displays information about those vessels, including their name, type, heading and speed.  The radar uses two radio beams, an S-Band at 3050 MHz and an X-band at 9410 MHz, to determine the location of the vessel relative to other vessels and landmarks within a 1% margin of error.

Gyrocompasses:

A standard compass points to the magnetic north pole rather than true north, therefore mariners prefer to use gyrocompasses for navigation.  Before departing, a gyrocompass is pointed to true north.  Using an electric current, the gyroscope in the device is spun very fast so that it will continually maintain that direction during the voyage.  Slight errors build up over time and must be corrected.  The watch standers post the necessary correction on the bridge.  Since the device is electronic, it can feed data into the system allowing for automated navigation and dynamic positioning systems to work well.

On the Electronic Chart Display Information System (ECDIS) screen, watchstanders can view the course planned by the Expedition Coordinator in charge of the science conducted on the voyage (in red), see the bearing they have set (thin black line), and see the actual course we are on (the black, dashed, arrowhead line).

The dynamic positioning system allows the vessel to remain in one spot in very delicate situations, such as when they lower a tethered device like the robotic vehicle they will be using on the next cruise or a CTD (Conductivity, Temperature and Depth probe).  It is also helpful for docking.

The electronics are able to control the ship due to the ingenious way the engine system is designed.  The diesel engine powers generators that convert the mechanical energy into electrical energy.  This way electrical energy can be used to control main hydraulic propellers at the stern as well as electric bow and side thrusting propellers.

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What happens if the power goes out and the electronic navigation devices fail?  There are back ups – no worries, students and family!!

The vessel can sail onward.  It is equipped with a magnetic compass and the watchstanders are well versed in reading charts, using a sextant, and plotting courses by hand – they often do that just to check the radar and GPS for accuracy.

They also have a well-used copy of the “bible of navigation,” The American Practical Navigator written in 1802 by Nathaniel Bowditch.

They even let me take it for a spin – okay it was about a 90˚ turn – but hey, it feels pretty cool to be at the helm of a 224ft vessel!

So where are we right now?

As I said we have begun mapping in our second priority zone, more than 100 miles north of Puerto Rico.  We are near the boundary of the Sargasso Sea.  It is not bordered by land, like other seas.  Instead it is bordered by ocean currents that keep the surface water in one area.

Remember the seaweed I wondered about in an earlier post?  It is called Sargassum.  It grows in rafts in the Sargasso Sea.  This is actually where the Sargasso sea got its name.  According to NOAA’s National Ocean Service, these rafts provide habitat for certain fish and marine life.  Turtles use them as nurseries for their hatchlings.  In recent years large blooms of Sargassum have been washing up on nearby coastlines causing problem along the shore.  (Oct 1, 2014, USA Today)  More research needed!  There are always more questions.  Is this caused by warming oceans, by oil spills, or by a combination?  Nothing lives in isolation.  All life forms are connected to each other and to our environment.  Changes in the ocean impact us all, everywhere on the globe.

 

Want to explore yourself?  Check out NOAA Corps to become ship officer!

Career Profile of a NOAA Corps Officer:

Acting Executive Officer (XO) Lieutenant Fionna Matheson is augmenting on this leg of the trip, meaning she is filling in for the XO currently on leave.  Otherwise, in her current “land job” she works at NOAA headquarters for the NOAA Administrator, Dr. Kathryn Sullivan.  Dr. Sullivan, a former astronaut and the first American woman to walk in space, reports to the Secretary of Commerce, Penny Pritzker. Working on the headquarters team, LT Matheson learns a great deal about the breadth and importance of NOAA’s mission.

To become a member of the NOAA Corps you must have a Bachelor’s degree in Science or Math. It is a competitive process, so some sort of experience with boating is advantageous, but not required.  NOAA Corps officers are trained not only to drive and manage ships, but also to handle emergencies including fire-fighting, and follow maritime law.  They act as the glue between the scientists and the crew (wage mariners), making sure the scientific mission is accomplished and the safety of the crew and the vessel are secure.  Fionna has been part of the corps for 11 years.  She explains that NOAA Corps officers are stationed for about 2 years at sea (with some shore leave) followed by 3 years on land throughout their careers. During her NOAA career, Fionna has sailed in the tropical Pacific maintaining deep-ocean buoys, fished in the North Atlantic, collected oceanographic samples in the Gulf of Mexico, and now mapped part of the Caribbean. She has also worked as part of an aerial survey team in San Diego, studying whales and dolphins.

Fionna’s advice to high school students is this, “The difference between who you are and who you want to be is action.  Take the initial risk.”

Personal Log

What do we do for fun in our free time?

We read.

We play games like chess, although I am not very good.  I try, and that is what is important, right?

We watch movies – even watched Star Trek on the fantail one evening.   Very fitting since we are boldly going where no one has gone before with our high-resolution sonar.

And we watch the sun go down on the ocean.

Mostly, I like watching the water when I have time.   I would have made a great lookout – I should look into it after I retire from teaching.  I have been trying to use my Aquaman powers to summon the whales and dolphins, but so far – no luck.   Maybe on the way back in to shore we’ll catch another glimpse.

What do I miss?

My family and friends.  Hi Bryan, Ben, Laura, Dad, Mom, and the rest of the gang.

And my students and coworkers.  Go Ashland Oredockers!

I am fortunate to have such supportive people behind me!  Thanks, guys!

I do not miss snow and cold weather, so if you all could warm it up outside in northern Wisconsin over the next week, I’d appreciate it.  I’ll see what kind of strings I can pull with these NOAA folks!   ¡No me gusta la nieve o el frío en la primavera!

Did you know?

Sky conditions on the bridge are determined by oktas.  An okta is 1/8th of the sky.  If all oktas are free of clouds the sky is clear.  If 1-2 oktas contain clouds, the bridge reports few clouds, 3-4 filled oktas equal scattered clouds, 5-7 equal broken clouds, and 8 filled oktas means the sky is overcast.

Question of the Day