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Sabrina Whitaker: Hands on the Helm, August 28, 2026

NOAA Teacher at Sea

Sabrina Whitaker

Aboard NOAA Ship Thomas Jefferson

August 18 – 31, 2026

Mission: Hydrographic Survey, Leg 3

Geographic Area of Cruise: The Great Lakes

Date: August 28, 2026

Weather Data from the Bridge

Latitude: 43°22.5312’N

Longitude: 076°43.7097’

Winds: 5 knots SW

Temperature:  75 F

Science and Technology Log

Executive Officer Chris Duffy looking over the planned survey for the day

Executive Officer (XO) Chris Duffy greeted me as I climbed the stairs to the bridge with, “The best job on the boat!” and then promptly asked if I wanted to drive the ship. I asked for a tour of the bridge first. He pointed out the main engine and auxiliary engine and then spoke about how it was especially beneficial to use the auxiliary engine in tight spaces for a finer control of the ship. He also pointed out the ship’s communication system including two radios and then he showed me the two radars. There are two different radars and each works with a different frequency. One is a higher frequency (X-band with a frequency of about 10 GHz)  and one is lower (S-band which is around 3 GHz). The X-band radar is used for collision avoidance and can even help identify some weather patterns like rain that is coming in. The S-band radar is used more to see bigger things like large ships further away or in bad weather.  I was surprised by how easily the ship turned under my hand. I was only making adjustments of 5-15 degrees from the center of the ship and yet she turned around easily and quickly.

View from the Bridge

Then, he showed me the navigation system. It is possible to control the ship “in hand” and that means a person is controlling the ship’s motion instead of the computer. There is also an “auto” feature, which can set the ship on a heading and the ship will continue on that heading forever or until someone gives the ship’s computer another parameter. And finally, there is a different type of auto navigation, where the ship follows a predetermined path like if you could have your car follow a Google Maps route without having to touch the steering wheel. This setting is referred to as “nav nav” because you press the “nav” button twice. When this setting is used, the map is usually created by those down in survey because they have two programs running. One is seeing where the SONAR swath has been and they have the software that runs nav nav as well, which is also shown on the bridge. 

My chance at the helm

Once I got familiar with the bridge, it was my turn. XO called out angles, “Right 15 degrees rudder” and I would follow his instructions, and then he would call out another angle, “Right 5 degrees rudder,” until we got the ship turned around so we could collect the next line of data with the multibeam. 

I wasn’t really sure how the angles and the directions were being decided because I couldn’t picture it in my head. So, just like in my own classroom, XO pulled out a whiteboard and gave me a mini-lesson on what he was doing. I thought this would be a good chance to show his teaching in action, so the video of the impromptu lesson is below.

Personal Log

Having spent years working with the American Physical Society to recruit physics majors, I am always on the lookout for physics in the real world. National graduation numbers highlight a stark gap: in the 2024–2025 academic year, only about 8,100 students earned a bachelor’s degree in physics, compared to roughly 141,000 in engineering. Yet, physics graduates are essential for advancing fields like quantum computing, fusion energy, and artificial intelligence.

While I have loved seeing hands-on physics applied across the bridge, survey room, and engine room, I was especially thrilled to meet someone using their physics degree outside of academia: Operations Officer Mark Meadows.

Operations Officer Mark Meadows as he collects a sample from the bottom of the lake

Mark discovered NOAA while completing his undergraduate degree. After participating in a research cruise, he fell in love with life at sea and applied to the NOAA Commissioned Officer Corps. The Corps requires officers to hold a college degree with at least 48 semester hours in STEM coursework.

After completing basic officer training, Mark joined NOAA Ship Thomas Jefferson as a junior officer, mastering ship handling, watchstanding, and maritime operations. Now in his sixth year with NOAA, he serves as one of two Operations Officers on board, helping lead ship operations and troubleshoot complex challenges.

What Mark loves most is how seamlessly his role blends seamanship with active science. On any given day, NOAA Corps officers work side-by-side with the hydrographic survey team—deep in data acquisition, processing, and “sheet” management (how we break down survey areas)—while simultaneously steering the ship, running small boats, and leading maritime operations.

Another huge draw of the NOAA Corps is its unique career rotation: officers typically complete a two-year sea assignment followed by a three-year shore assignment. This cycle gives them hands-on experience across the entire agency, allowing them to bring real-world operational insight into land-based research, policy, and management roles before heading back to sea.

Did You Know?

The hydrographic survey crew frequently detects shipwrecks in their multibeam SONAR data. We recently mapped one during our run:

Shipwreck detected by SONAR
A Shipwreck by the SONAR

While raw SONAR images can take a moment to interpret, comparing the structural outlines to a ship’s internal frame brings the target into focus. As processing continues, the survey team will clean up the imagery and all the detailed information (location, depth, dimensions of the wreck, imagery, etc.) is packaged up and sent to the State Historical Preservation Office (SHPO). They will then assess whether the wrecks have historical significance.   

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Sabrina Whitaker: Small Boats, Big Data, August 26, 2026

NOAA Teacher at Sea

Sabrina Whitaker

Aboard NOAA Ship Thomas Jefferson

August 18 – 31, 2026

Mission: Hydrographic Survey, Leg 3

Geographic Area of Cruise: The Great Lakes

Date: August 26, 2026

Weather Data from the Bridge

Latitude: 43’’53’34.7740° N

Longitude: 76”30”07.8526° W

Winds: 5 knots

Temperature:  70 F

Science and Technology Log

Today, I had the incredible experience of going out on one of the survey launches with Hydrographic Survey Tech Haley Kenyon and Ensign James Hutzenbiler to run side-scan sonar. We rely on these smaller boats particularly when the water becomes too shallow for NOAA Ship Thomas Jefferson to maneuver safely or when we are working in areas where the depths are completely unknown.

Sabrina, wearing a hard hat and life vest, poses for a photo with her hands on the rail of the small launch vessel. it is sunrise, and the sky has bands of pink and yellow near the horizon.
Aboard the small boat and ready for the day!

Once underway, Ensign Hutzenbiler and Haley navigated our assigned lines with incredible efficiency. 

a man stands at the helm of the small launch vessel, two hands on the steering wheel, facing out the front of the boat's cabin
ENS Hutzenbiler drives the launch

When we ran into an issue with our POS (Position and Orientation System) data, Haley had Ensign Hutzenbiler hold position while she stepped out to secure an antenna connection with electrical tape. 

view up a large antenna toward a blue sky with wispy white clouds; a woman wearing a life vest stands behind it with one hand grasping it above her head
Survey Tech Haley Kenyon secures the antenna

When the glitch popped up again later, a full system reboot got us back online for the rest of the day. The ingenuity, calm troubleshooting, and seamless teamwork on that small launch were inspiring—and together, they logged over 70 nautical miles of high-quality bathymetric data.

photo of a computer screen displaying the survey lines, color coded by measured depth, overlaid on a nautical chart
software displaying survey lines
view of NOAA Ship Thomas Jefferson from behind the stern, with the front deck of the small launch vessel visible in the foreground
View of NOAA Ship Thomas Jefferson from the launch vessel as we return to the ship

Personal Log

Before we even stepped foot on the launch, we went through a comprehensive risk assessment using a GAR (Green-Amber-Red) model.

The colors represent our overall risk score:

  • Green (0–23): Low risk; proceed with standard precautions.
  • Amber (24–44): Moderate risk; requires consultation with the Executive Officer (XO) and crew to implement specific risk mitigations.
  • Red (45-60): High risk; the launch does not deploy unless risks can be successfully mitigated to lower the score.
photo of a printed sheet of paper that reads FLOAT PLAN, Date 8/26/26. HSL 2903/2904 (with "2904" circled in pen.) the plan lists information about the launch vessel, Passengers and Crew, Itinerary, and Operational Risk Management.
Float Plan, including the GAR risk assessment, for launch vessel 2904

The GAR sheet is led by the coxswain—the officer in charge of the vessel—but it is a collaborative discussion. Once our mission for the day is outlined, the entire crew reviews every safety factor together.

8 or 9 people sit and stand around a computer room on NOAA Ship Thomas Jefferson facing a NOAA Corps officer standing by a screen
The pre-launch small boat meeting

For my trip, the lake was calm and the mission was straightforward. I bumped our “Mission Complexity” score up slightly because it was my first time on the launch, meaning the team had to account for extra safety oversight for a newcomer. When weather conditions worsen—like on a day another crew faced choppy waters—the risk may elevate to Amber. If the risk does rise to Amber,  they thoroughly map out contingency plans—including designated safe-harbor ports along their route if conditions deteriorate. Thanks to that preparation, everyone is able to execute their missions and return safely. What impressed me most about the GAR process is its culture of open safety. If anyone—regardless of rank, role, or whether they are actually going on the boat—feels a risk factor is underestimated, they have the authority to raise the score. Crucially, a score can never be voted down by someone else; it can only be raised. Knowing that safety is actively evaluated from every angle made me feel completely confident heading out on the water.

That culture of psychological safety, open communication, and continuous learning is something I am eager to bring back to my physics classroom. My students spend a lot of time collaborating in lab teams, and I want to find a way to create an environment where every student feels just as empowered to speak up—whether it’s pointing out a safety oversight or double-checking a peer’s lab setup or providing feedback on solving a problem. I already model this by encouraging students to call out my own errors, but seeing how seamlessly the crew on Thomas Jefferson prioritizes collective growth has me reflecting on how I can cultivate that same deep trust in my classroom right from the start of the school year.

Did You Know?

Port is the left side of a ship or boat while starboard is the right side when facing the front (bow) of the ship as shown in the image below:

diagram of a boat seen from above, with labels identifying the bow (forward) at the front; the stern (aft) at the back; the port side at the left, and the starboard side at the right
From: https://www.saltwaterjournal.life/blog/port-and-starboard-sides

The port side of the boat is named so because that is the side of the boat that was traditionally tied up to the dock or port, opposite to the steering or steer board, “starboard.” https://oceanservice.noaa.gov/facts/port-starboard.html.

One of the crewmembers told me that to remember port and starboard to always remember that port has four letters in it and so does left, so they are on the same side of the boat. 

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Sabrina Whitaker, Food for Thought, August 24, 2026

NOAA Teacher at Sea

Sabrina Whitaker

Aboard NOAA Ship Thomas Jefferson

August 18 – 31, 2026

Mission: Hydrographic Survey, Leg 3

Geographic Area of Cruise: Lake Ontario

Date: August 24, 2026

Weather Data from the Bridge

Latitude: 43°53’38.2834N

Longitude:76° 30’08.8917W

Winds: Temperature:  68° F

Science and Technology Log

The science, travel, and community that make life aboard NOAA Ship Thomas Jefferson possible rely on the team hard at work in the galley. The cooks in the steward department serve a hot breakfast every morning at 7:00 a.m., offering eggs to order, pancakes or waffles, bacon, turkey bacon, sausage, and grits or oatmeal, along with fruit and a variety of sauces.

two people stand near a stovetop in the ship's kitchen area; the woman in the foreground, wearing latex gloves, uses a spatula to scrape eggs onto a plate
Some of the Steward Department serving breakfast.

At 11:00 a.m., they serve a wide array of lunch options. Tuesdays are usually Taco Tuesday—a crew favorite—though the menu varies based on what Chief Steward Danni Cuff creates. She posts the weekly menu in advance so everyone knows what to expect. This also allows crew members to request a plate to be saved if they are working on the small boats or on shift outside galley hours.

a scanned copy of a printed table showing the menus for breakfast, lunch, and dinner, Monday through Saturday. at the top, there is a note that reads: "Menu subject to change at weather & steward department discretion. your understanding is appreciated in advance!"
The menu for this week.

Dinner is served at 4:30 p.m. Last week featured a surf-and-turf dinner with crab legs and steak. It was my first time trying crab legs, and I have to say, I prefer them over lobster.

photo of a dinner plate containing steak topped with onions and mushrooms, two dungeness crab legs, asparagus, roll
Surf and turf dinner

For dessert tonight, I joined the Chief Steward in the galley to help make and decorate a white cake. Before we frosted it, she gave me some pointers on piping practice. Since she couldn’t find the exact piping tip she wanted, she also showed me how to cut a pastry bag to create one from scratch.

close up view of two gloved hands icing a round cake on a glass cake plate
Danni frosting the cake served for the evening dessert
close up photo of finished cake: white icing dotted with strawberries
A white cake with strawberries that was served for dessert about NOAA ship Thomas Jefferson.

The Chief Steward’s role extends far beyond baking. She manages her department and ensures her team receives professional development while in port; one of her crew members will soon attend training at The Culinary Institute of America. 

In addition to staff management, Danni oversees inventory and supply ordering for each leg of the voyage. She is currently developing an automated inventory system designed to generate supply orders and vendor lists based on planned menus and upcoming crew counts.

Personal Log

Before embarking on this leg aboard NOAA Ship Thomas Jefferson, one of my biggest worries was the menu. I don’t typically care for seafood and have actively avoided it in the past, so I even reached out to a past Teacher at Sea participant to ask about the food. It turned out to be a total non-issue for three reasons: 1. Danni consistently provides multiple lunch and dinner choices (as seen on the weekly menu), alongside a fully stocked salad bar and sandwich station; 2. She takes great care with dietary restrictions and allergies. With so many options available, personal preferences are naturally accommodated as well; and 3. I’ve actually found myself reaching for seafood intentionally. Danni has prepared my favorite—catfish—both grilled and fried, and served dishes I had never tried before, like pollock and crab legs. Looking at menus from previous months, I noticed even more local, sustainably sourced species I would love to try.

Danni puts incredible thought, care, and effort into her work, and everyone aboard NOAA Ship Thomas Jefferson deeply appreciates her dedication—and her delicious meals.

Did You Know?

A waterspout is a spinning, funnel-shaped column of air and water mist that forms over a large body of water. At the end of the day that I spent with Danni, we saw a waterspout off of the side of the ship.

a waterspout forming over the horizon above the gray waters of Lake Ontario
waterspout over Lake Ontario
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Sabrina Whitaker, Fixes on the Fly, August 22, 2026

NOAA Teacher at Sea

Sabrina Whitaker

Aboard NOAA Ship Thomas Jefferson

August 18 – 31, 2026

Mission: Hydrographic Survey, Leg 3

Geographic Area of Cruise: Lake Ontario

Date: August 22, 2026

Weather Data from the Bridge

Latitude: 43°22.554’N

Longitude: 76°44.490’W

Winds: South East Winds at 5-10 knots

Temperature:  77 F

Science and Technology Log

Taking care of the ship requires communication from all of the departments aboard the ship. The actual fixing and maintenance of the ship requires the Engineering department. As I followed Oiler Sam Fuller around for the day, I was introduced to just how much is involved in caring for the ship. The engineering department ran through the list of what needs to be tackled for the day and what projects are upcoming or ongoing. They make sure everyone knows what to look out for and discusses the tasks to accomplish. 

Just like the rest of the ship, the day starts off with a meeting. 

four people stand around a large table in a workshop in the engine level. we see stacks of labeled drawers beneath the table and on the walls, tools mounted on the walls and hanging from the ceiling.
Some of the engineering department: From left to right – Junior Unlicensed Engineer Mike Pienta, Chief Marine Engineer John Toye, Oiler Sam Fuller, 1st Assistant Engineer Brian Maddrey

Once the morning meeting was over, Sam took me through a few of the tasks he completes each day. First, he tested the chlorine in the water from the Reverse Osmosis system. They had been having trouble getting the chlorine high enough over the last few months, but today’s reading was finally right on track. Sam made sure to show me the chlorine that gets added to the water and pointed out that I should never be near it without gloves, mask, or goggles because of how dangerous it is. He also let me know that the chlorine added is further from the part of the ship where water is actually used by people because it means more chances to correct for a possible problem. 

Sam stands at a workbench and examines a small glass vial filled with pink liquid
Sam testing the water for chlorine levels

Then, the engineers showed me how to move the ship’s power from one generator to another. It’s a complicated dance of syncing up the generators so that there is no sudden loss of power to the ship while the next generator comes online. It also prevents catastrophic failure of either generator while one generator slows down and the other takes over. 

view of the generator panels with many dials and switches. on the floor is a small carpet featuring the seal of NOAA Ship Thomas Jefferson
Generator panels

Then, I got a tour of the engine room. The engine for the ship is massive and it is loud in the engine room. We both wore ear protection while touring the engine room and Sam showed me around. 

main propulsion engine viewed from above
Thomas Jefferson’s main propulsion engine viewed from above
main propulsion engine viewed from the side
Thomas Jefferson’s main propulsion engine viewed from the side

Then, it was on to Sam’s projects for the day. One of these projects was to better secure the weights in the gym. He and one of the chief engineers want to create something where several weights can be secured by going through a pipe so they do not move as much. He envisions 4 pipes on a base plate for the weights they have. We went down to measure the weights, and the spacing on the wall so that he could cut and weld everything appropriately.

view inside the weight room. Sam stands toward the back wall and holds up a piece of paper near a shelf.
NOAA Ship Thomas Jefferson’s gym, which is available to anyone at any time. Sam is taking measurements for the weight holder project

Once he had the measurements, he put the project aside so that he could wait for one of the chief engineers to come on shift. In the meantime, he went to the survey room to fix an air conditioning condensate pump that broke and caused it to leak water over the computer of one of the Senior Survey Technicians. Previously, a condensate drainage tube had been placed to take care of the problem and the condensate water drained into the bucket over time and then was emptied outside. Sam was able to replace it because they got the necessary part in when they were last docked. 

Sam, probably standing on a chair or stool, reaches up to install the air conditioning condensate pump at the ceiling above a desk area
Sam installing the pump
view of an electrical box mounted on the ceiling with its panel open and hanging down; on the inside of the panel is a printed circuit diagram
The circuit diagram and electrical system for the unit Sam is installing the pump in.

Once the pump was installed, Sam went downstairs to start cutting the pieces necessary for the gym weight project.

Sam using a circular saw to cut a piece of particle board
Sam cutting down the base of the weight holder

Sam had a few things cut but then the survey room called and condensate water was leaking again in the survey room. It turned out that the pump was not enough to adjust for the motion of the ship. The pump that broke was meant to make it so that the water went back through the pipe the other way, but it couldn’t because of the elevation of the pipe compared to the other units in the room. The Engineering department decided to install a check valve that allows the water to only flow in one direction. This would make it so that the majority of the water did not make it to the lowest unit in the room and would prevent it from flooding that system. Sam grabbed supplies and started on the repair right away. The Engineering department has enough tools and replacement parts that it can make many repairs while underway and they make sure to keep the ship livable and comfortable without having to wait to take the ship in for repairs.


view of tools - maybe power drills - mounted in holders on a wall
view down blue metal cabinets with each drawer labeled
a collection of many wrenches hanging from pegs lining a workbench
Sam and another engineer stand looking through an open drawer filled with round pipe parts
view of blue metal cabinets filled with many neatly-labeled drawers
Sigh, the organization to which I aspire to. I’m going to print out these pictures and paste them on the door to our garage as I reorganize it.

Once the necessary tools and supplies were collected, they got to work.

Sam stands on a metal stepladder and reaches his hands up to the pipes running along the ceiling; another engineer wearing a NOAA Ship Thomas Jefferson t-shirt stands on the ground nearby to assist
two people reach up toward a series of pipes running along the ceiling
one engineer reaches up to cut a pipe on the ceiling with a large pair of pipecutters; Sam stands on the ladder and steadies the pipes with his hands
close-up view of newly installed valve
Installation of the new check valve

Sam returned to his project for the gym until the small boats came in. At that point, anyone who can is asked to come out on deck so they can help if needed while the small boat is put back on the davit. Engineering is especially important in this process and they keep a watchful eye over the process.

Small Boat Retrieval

After the small boat has been returned to the davit, the engineering department goes over the boat and refills it with fuel, checks the oil, and checks how long it should be until the next maintenance period for the engine. They pass on any problems they find to the crew and it is discussed at the morning meeting the next time the boats are sent out.

two engineers on the small vessel
Engineering checking the fuel on the small boats.
Sam, down in the engine bay of the small launch vessel, reaches one hand underneath the floor panels while another, outstretched, holds a rag
Engineering checking the oil and going over the small boats in detail.

Eventually, Sam was able to begin the process of welding the pipes to the stand that would hold the gym weights. It’s important to place a call to the deck officers and let them know that that type of work is being done so that they don’t worry about a burning smell but also to be aware of any potential for fire so it can be stopped should something go wrong. Again, safety, especially around fire, on a boat is treated very carefully.

Sam, wearing a helmet and heavy gloves, welds in a workshop room
Sam welding the pipe to the base plate for the gym project.
close up view of a pipe welded to a baseplate; the connection point is still glowing hot
The welded metal after welding.
close up view of the welded connection between the end of the pipe and the base plate
The welded pipe to the base plate.

Personal Log

One of the biggest things that has struck me throughout my time on ship is the huge number of opportunities aboard. The engineering department has one of the best options for vertical movement on the ship because you can start as a wiper or an oiler. Sam started at NOAA by going through the job corp and then joining NOAA as an Oiler. However, that is not the only way to enter into a NOAA engineering department position. Several other engineers came in after serving time in the Navy or Coast Guard and then moving to NOAA and others came in without military experience and joined with experience in other fields instead. The important thing is that they obtained their merchant mariner credential (MMC), which provides proof of their qualifications, which includes their physical readiness as well. More information on obtaining an MMC is found here: https://www.dco.uscg.mil/nmc/merchant_mariner_credential/

Did You Know?

Those working aboard NOAA ships get paid overtime for anything over 8 hours of work completed Monday through Friday and they get overtime for working Saturdays, Sundays, and holidays, too. The jobs listed at https://marinerhiring.noaa.gov/Jobs/Openings list base pay, and while overtime is not guaranteed, it often accounts for up to twice the base pay for a given position. The other benefits for working for NOAA are also numerous as well. For example, while on ship, most incidentals are paid for. There is no need for a car or paying for fuel, all food is paid for while at sea, the ships have Starlink, so internet is fast and hasn’t been any less reliable than my home internet, and of course lodging aboard ship is included as well. The professional mariners are on 2 month rotations and then have a month of shore leave, where as one crew member put it, “I cook, clean, and have no other responsibilities.”

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Sabrina Whitaker: Night Life, August 20-21, 2026

NOAA Teacher at Sea

Sabrina Whitaker

Aboard NOAA Ship Thomas Jefferson

August 18 – 31, 2026

Mission: Hydrographic Survey, Leg 3

Geographic Area of Cruise: Lake Ontario

Date: August 20-21, 2026

Weather Data from the Bridge

Latitude: 43°22.554’N

Longitude: 76°44.490’W

Winds: South-South East at 5 knots

Temperature:  60° F

Science and Technology Log

I spent the overnight shift with Hydrographic senior survey technician Emily Madish tonight. Her shift starts at 3:30 p.m. and goes until 3:30 a.m. She worked with two other crew members in the survey room: Operations Officer Jessie Spruill and Hydrographic Survey Tech Hannah Hernandez. There were more members of the crew on the deck navigating the ship through the dark waters. 

a woman sits at a desk facing an array of 7 computer monitors
Emily keeping track of the ship and the data coming in

I took the opportunity of the quiet evening and having fewer people around to have Emily walk me through the process for collecting data on NOAA Ship Thomas Jefferson and to explain how the scientific equipment on the ship works to collect depth data. 

Hydrographic surveys make use of a variety of fundamental physics concepts. One of them is how sound travels. Sound travels at a constant speed through a medium (a material like water or air) unless the properties of the medium change. In lake or ocean water, properties that could change the speed are the salinity, temperature, and depth. Thomas Jefferson accounts for these possible changes by collecting that information using the Moving Vessel Profiler (MVP) and collecting that data approximately every hour so that the data collected by the ship can use the most accurate information to create the depth profiles. 

three graphs in a row with different x-axes: sound speed (meters per second), temperature (degrees Celsius), and salinity (practical salinity units), all versus the same y axis of depth in meters
This is the graph the MVP software displays, collects, and transfers to other software that works in conjunction with the MVP. This is one of the casts taken from Thomas Jefferson

Once the speed of sound in the area has been collected, the time it takes for the sound to go to the bottom of the seafloor (or in this case lakebed) is collected. From there, the depth of the seafloor can be calculated using the equation:

Velocity equals depth over time

To solve for depth, it becomes

depth equals velocity times time

However, the time included at this point includes both the time leaving the ship and going to the seafloor and back again, which can be visualized like this: 

illustration of a ship at the surface of the water sending out sound waves, shown as solid arcs, to the seafloor, and those sound waves bouncing back (shown as dotted arcs) toward the ship
(image from: https://www.americanoceans.org/facts/what-is-sonar/)

To account for the reflection, the time that is collected is cut in half and the new equation becomes:

depth equals velocity times time divided by 2

(Note: hydrographers use different letters to represent these variables, but I’m keeping everything in notation my high school students are or will be familiar with. They mean the same thing.)

Now, this seems relatively straight forward so far. However, what is really cool is that the ship is not taking just one sounding (depth measurement). Instead, the ship is sending out SONAR in a fan shape using a multibeam or side scan, which can be visualized as follows: 

illustration of a swath of sound waves emanating from beneath a ship and sweeping over the seafloor to different depths
Typical geometry of bottom tracking multibeam sonar. 
Image from Mayer, Larry & Li, Yanchao & Melvin, Gary. (2002). 3D visualization for pelagic fisheries research and assessment. ICES Journal of Marine Science – ICES Journal of Marine Science. 59. 216-225. (ResearchGate)

This allows not only the various depths of the sea floor to be collected, but because many (MANY) soundings are taken at once, the soundings can also translate into images and an image of the seafloor can be created. In addition to an image of the seafloor, it is also possible to find out if there are any hazards to shipping or features on the seafloor. For example, in Lake Erie on the last leg of the mission a lot of shipwrecks were seen, and while there haven’t been any shipwrecks found on my leg as far I know, some features of the lakebed, like glacial scarring may have been seen, along with a lot of rocks. A lot of rocks. 

photo of a computer screen displaying color-coded depths readings along a band of the seafloor (lakefloor)





The path of the ship (yellow and green, this also shows the depth of the area as well) and an initial image of the seafloor.
soundings data shown in black and white - there are diagonal bands across this swath
Notice in the black and white image the possible glacial scarring that can be seen).

It is also possible to see schools of fish in the water column or capture an image of a whale with the multibeam or sidescan.

photo of a laminated page attached to a wall with magnets. the printed page displays side scan sonar readouts - divided by a white band in the middle where the ship is located - and the scanned image shows mostly soft rippling of a seafloor, with one very distinct white whale-shaped silhouette to the left of the ship. the page is titled: "A Whale, Captured in Side Scan Sonar Imagery!!!"
A picture of a side scan that shows a whale that is displayed on Thomas Jefferson

To get to the point of creating an image and having the image accurately represent the location of where the data was taken to create a meaningful map, while also correcting the data for errors and the motion of the ship requires many steps. 

First, the Seafloor Information System collects real time depth data being collected by the multibeam sonar, while HYSWEEP communicates with the bridge. Those in survey use HYPACK to make planned survey lines, and those on the bridge use HYSWEEP and follow those lines. The bridge and the survey team are in constant communication while this process is ongoing.

photo of a computer screen displaying the output from the HYSWEEP software. there is a straight red line showing the ship's trajectory, across a wide blue field representing the lake. the ship's position is noted on the line, and behind it is a band of depth readings.
The path as shown in HYSWEEP that both the bridge and the survey team can see

Thomas Jefferson travels back and forth like someone mowing their yard with long back and forth lines that overlap by about 20% to make sure that no areas are missed. 

photo of a computer screen displaying two different swaths (passes of the ship's sonar readings) overlapping on the same field. the readings are color coded by depth.
This is the second swath the ship makes as it goes past the same location as the image above with the glacial scarring

The ship also collects what is called crosslines, which must be collected for every 4% or 8% of the lines collected that are parallel to each other, depending on the spacing between the lines, to make sure that the data remains reliable. It is possible the parallel lines could be offset from each other and the crosslines ensure that they are not. 

photo of a computer screen displaying collected sonar readings; many of the lines are parallel sweeps, but there are also diagonal lines that cross over these and help true the data
An entire sheet that shows where data was collected including crosslines (the diagonal lines) and the lines parallel to each other

Once the data is collected, the data from GNSS including GPS and information from other satellites is collated with the ship’s depth data. This involves a lot of additional software that ensures the accuracy and fidelity of the information being collected. 

After everything has been processed, it is sent to NOAA for further integration into the maps that allow ships navigating the waters carrying people and goods across the Great Lakes stay safe. Progress on the Great Lakes project and other hydrographic survey projects can be found at: https://storymaps.arcgis.com/collections/855b7102bd0d42d6974c41fa4f8829b9?item=5

Personal Log

It’s fascinating to notice how life aboard the ship mirrors research experiences I’ve had elsewhere. During my undergraduate and graduate work, I spent night shifts at Brookhaven National Laboratory and Argonne National Laboratory running experiments at the synchrotrons. The late hours aboard the ship feel remarkably similar.

Night shifts have a distinct stillness. Instead of the busy daytime chatter and people moving about, the ship settles into a steady rhythm defined by the deep hum of instrumentation and running equipment. Monitors glow with data software, and as the end of the shift approaches, fatigue sets in—making it just a little easier to make a minor mistake (though usually the mistakes are fixable). Sometimes it even feels like the software itself gets tired of being up that late and starts acting up. But through it all, really cool data is collected despite anything else that happens.

Did You Know?

NOAA Ship Thomas Jefferson is sent out after natural disasters like hurricanes, to help ships enter and exit ports. The ship helps make certain that there are not any dangers to ships from the disaster, so that rescue, shipping, and reconstruction after the disaster can proceed. 

a poster about NOAA Ship Thomas Jefferson's response after Hurricane Maria, featuring an annotated nautical chart of Puerto Rico and the U.S. Virgin Islands
NOAA Ship Thomas Jefferson Hurricane Maria Response, 2017. View full PDF version.