salinity – NOAA Teacher at Sea Blog

April 28, 2023April 29, 2023

Julie Hayes: Days at Sea! April 26, 2023

NOAA Teacher at Sea

Julie Hayes

Aboard NOAA Ship Pisces

April 22-May 5, 2023

Mission: SEAMAP Reef Fish

Geographic Area of Cruise: Gulf of Mexico

Date: April 26, 2023

Weather Data

Clouds: Scattered

Temperature: 77 degrees F

Wind: 12 kt.

Waves: 2-4 ft.

Science and Technology Log

Each day is started and then ended with a water sample from the ocean. The technology is called a CTD, but the procedure would be called a CTD cast (as if we were casting it in the ocean). CTD stands for conductivity, temperature, and depth. The CTD consists of a collection of electronic instruments that measure the properties of the water, including a laser that checks the clarity of the water. Sampling water bottles are connected to a metal frame called a “rosette”. This information on water characteristics is important to both the scientists and the survey mapping team that use cameras and sonar. This information lets them know how well the clarity of the water is and the speed of sound that helps with the depth finders and sonar.

The apparatus containing the conductivity, temperature, and depth probe sits on the deck of NOAA Ship Pisces, awaiting deployment. — CTD used to check water quality, conductivity, temperature, and depth.

Vocabulary Check

What is Conductivity?

Conductivity is a measure of the ability of water to pass an electrical current.

What is Salinity?

Salinity is the dissolved salt content of a body of water and is a strong conductor of water.

So why is it important for scientist to know what each of these are?

The higher salinity the water is, the higher the conductivity of electrical currents.

Temperature also plays a role in the density. Knowing each of these is important because it lets the scientists know the water quality at different depths so they can make adjustments to their cameras and sonar.

Jack Prior, Chief Scientist

Jack is a pretty “chill” guy, and I have enjoyed watching him in action the past few days. Jack is the field party chief of this mission which involves everything from planning the trip, to deciding the daily sampling locations, deploying cameras, mapping, and figuring out what to do when things go wrong. Jack is in charge of planning and submitting the protocol for the entire mission and also is responsible for the end reports of the mission. You will find Jack on this leg sitting behind multiple computers regulating and keeping a watchful eye on all of the important information regarding this mission. Jack attended the University of West Florida to get his degree in marine biology.

Jack sits at a computer desk with multiple monitors. He smiles at the camera, his right hand giving a thumbs up. — Chief Scientist Jack Prior

Student Question of the Day

Whenever I get a chance, I ask random crew members questions that my students back home were curious about. Here is how Jack answered some of the students’ questions.

Konnor, Nichole, Lillian ask: What degree do you have and what all is needed to do your job?

Jack started his major in biology and had originally planned on going on to be a pharmacist, but then moved to Florida where he ended up getting his degree in marine biology instead. Jack continued to also get his Masters at the University of West Florida, too. Jack changed his career path because he enjoyed marine life. Volunteer work is crucial to get experience, and can benefit you on becoming more diverse when it comes to getting a job in marine biology.

Alyson asks: What would be your dream job?

Someday Jack wants to explore the seafloor in a submarine.

Blake, Sailor, Lilli, Jenna ask: What is your favorite food on the ship?

Taco Tuesdays seem to be a huge hit on the ship, as well as Friday pizza day.

Auburn, Ashton M., Karson, Liam: What would you consider to be the coolest marine life you have seen?

Seeing large diverse reef habitats is what Jack says he finds the most interesting, especially uncommon invertebrates that you’d never see on the beach.

Jaxon and Dwight: Can you be on the ship if you have health issues and what happens if there is a medical emergency?

The ship is a pretty confined space with steep stairs, uneven footing, areas you have to be able to step over, and have the ability to carry heavy weight. If there is ever a medical emergency, the ship works alongside the United States Coast Guard to get them the help they need. However, the ship is great working with all issues and plans accordingly to those who may have special diet restrictions.

Personal Log

Well, I will say that I am getting better at having my sea legs but that is still a work in progress. I have really enjoyed getting to understand the life on this ship, and I am just amazed at how diverse everyone is and yet still make this an amazing environment. It has taken me a few days to get the hang of where things are and to get out of my comfort zone to ask what I feel like has to be a million questions about everything. I have really enjoyed getting to hear and learn about the crew’s background and how they ended up on NOAA Ship Pisces. I greatly appreciate their willingness to answer my questions, even though I am sure I am in their way at moments. Everyone has a job to do and work different hours and shifts. It is great to see how they all respect each other’s space and sleeping hours.

There is so much science around me that I never knew existed, and I am shocked on how much technology is actually being used and heavily relied upon. Today was the first day the waves were calm enough that I was able to go out on the stern (learning names of different areas of the ship) to work on the blog and soak up a little bit of Sun. It was nice to be able to get some fresh air. The food has been amazing on the ship. I love how everyone is so courteous by thanking the cooks, as well as cleaning up after themselves before leaving the mess. The mess is the area in which we eat and the kitchen is called the galley. It has taken me a few days to understand the boat “lingo” but I am starting to catch on. The stairs are pretty steep, and everyone on board says to use 3 points of contact when walking. This is so that if they hit a wave while walking you are more stable. I could definitely see this being an issue going up and down the stairs. The doors are super heavy and I am still learning how to get those twisted and sealed tight the first time I close it (I am getting there).

A view of the mess: that is, the ship's the dining area. At the moment, it is unoccupied. There are five long tables, bolted to the floor, covered in blue vinyl or plastic table clothes. Black chairs surround each one. The chair's legs are all capped in cut-open tennis balls. The tables are supplied with condiments and paper towel holders. A large television screen mounted on the wall shows a football game. — The mess where we eat. It is spotless and a great size to fit everyone on board.

A staircase, as seen looking down from the top stair. There are railings and anti-slip applications.

A heavy metal door, with rounded edges, and a steering-wheel shaped handle. The door is stamped "Keep Closed."

August 28, 2017August 28, 2017

Amanda Dice: Ending Week 1 at Line 8, August 26, 2017

NOAA Teacher at Sea

Amanda Dice

Aboard Oscar Dyson

August 21 – September 2, 2017

Mission: Juvenile Pollock Fishery Survey

map cropped — *Oscar Dyson* moves across the Shelikof Straight to collect the Line 8 samples

Geographic area of cruise: Western Gulf of Alaska

Date: August 26, 2017

Weather Data: 13.2 C, cloudy with light rain

Latitude 57 36.6 N, Longitude 155 .008 N

Science and Technology Log

As part of this survey, the scientists onboard collect data from what is known as “Line 8”. This is a line of seven sampling stations, positioned only a few miles apart, near the southern opening of Shelikof Straight between Kodiak Island and the Alaskan Peninsula. Water samples are taken at different depths at each sampling station to measure several different properties of the water. This study is focused on profiling water temperature and salinity, and measuring the quantities of nutrients and phytoplankton in the water.

The CTD rosette is lowered into the water using a winch – as seen from above.

To collect this data, a conductivity and temperature at depth (CTD) instrument is lowered into the water. This instrument can take water samples at different depths, by using its eleven canisters, or Niskin bottles. The water collected in the Niskin bottles will be used to determine the nutrient quantities at each station. The rosette of Niskin bottles also has sensors on it that measure phytoplankton quantities, depth, temperature, and how conductive the water is. Scientists can use the readings from conductivity and temperature meters to determine the salinity of the water.

Each Niskin bottle has a stopper at the top and the bottom. The CTD goes into the water with both ends of each Niskin bottle in the open position. The CTD is then lowered to a determined depth, depending on how deep the water is at each station. There is a depth meter on the CTD that relays its position to computers on board the ship. The survey team communicates its position to the deck crew who operate the winch to raise and lower it.

Niskin bottles are lowered into the water with the stoppers at both ends open.

When the CTD is raised to the first sampling depth, the survey crew clicks a button on a monitor, which closes the stoppers on both ends of Niskin bottle #1, capturing a water sample inside. The CTD is then raised to the next sampling depth where Niskin bottle #2 is closed. This process continues until all the samples have been collected. A computer on board records the depth, conductivity and temperature of the water as the CTD changes position. A line appears across the graph of this data to show where each sample was taken. After the Niskin bottles on the CTD are filled, it is brought back onto the deck of the ship.

They let me take control of closing the Niskin bottles at the sampling depths!

CTD screen cropped — I used this screen to read the data coming back from the CTD and to hit the bottle to close each Niskin bottle. The purple horizontal lines on the graph on the right indicate where each one was closed.

Water is collected through a valve near the bottom of each Niskin bottle. A sample of water from each depth is placed in a labeled jar. This study is interested in measuring the quantity of nutrients in the water samples. To do this it is important to have samples without phytoplankton in them. Special syringes with filters are used to screen out any phytoplankton in the samples.

Screen Shot 2017-08-26 at 8.28.56 PM — Syringes with special filters to screen out phytoplankton are used to collect water samples from the Niskin bottles.

The “Line 8” stations have been sampled for nutrient, plankton, and physical water properties for many years. The data from the samples we collected will be added to the larger data set maintained by the Ecosystems and Fisheries-Oceanography Coordinated Investigations (Eco-FOCI), Seattle, Washington. This NOAA Program has data on how the marine ecosystem in this area has changed over the last few decades. When data spans a long time frame, like this study does, scientists can identify trends that might be related to the seasons and to inter-annual variation in ocean conditions. The samples continue to be collected because proper nutrient levels are important to maintaining healthy phytoplankton populations, which are the basis of most marine food webs.

Collecting water samples from a Niskin bottle.

Personal Log

As we travel from one station to the next, I have some time to talk with other members of the science team and the crew. I have really enjoyed learning about places all over the world by listening to people’s stories. Most people aboard this ship travel many times a year for their work or have lived in remote places to conduct their scientific studies. Their stories inspire me to keep exploring the planet and to always search for new things to learn!

Did you know?

Niskin bottles must be lowered into the water with both ends open to avoid getting an air bubble trapped inside of them. Pressure increases as depth under water increases. Niskin bottles are often lowered down below 150 meters, where the pressure can be intense. If an air bubble were to get trapped inside, the pressure at these depths would cause air bubble to expand so much that it might damage the Niskin bottle!

July 29, 2017August 15, 2017

Samantha Adams: Day 6 – Testing… 1 – 2 – 3, July 29, 2017

NOAA Teacher at Sea

Samantha Adams

Aboard NOAA Ship Hi’ialakai

July 25 – August 3, 2017

Mission: Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Time-series Station deployment (WHOTS-14)

Geographic Area of Cruise: Hawaii, Pacific Ocean

Date: Saturday, 29 July 2017

Weather Data from the Bridge:

Latitude & Longitude: 22^o45’N, 157^o56’W. Ship speed: 1.3 knots. Air temperature: 27.8^oC. Sea temperature: 27.0^oC. Humidity: 72%.Wind speed: 14 knots. Wind direction: 107 degrees. Sky cover: Few.

Science and Technology Log:

The most difficult part of Thursday’s buoy deployment was making sure the anchor was dropped on target. Throughout the day, shifting winds and currents kept pushing the ship away from the anchor’s target location. There was constant communication between the ship’s crew and the science team, correcting for this, but while everyone thought we were close when the anchor was dropped, nobody knew for sure until the anchor’s actual location had been surveyed.

blog.4.Day6.image1 — Triangulation of the WHOTS-14 buoy’s anchor location. Look at how close the ‘Anchor at Depth’ location is to the ‘Target’ location — only 177.7 meters apart! Also notice that all three circles intersect at one point, meaning that the triangulated location of the anchor is quite accurate.

To survey the anchor site, the ship “pinged” (sent a signal to) the acoustic releases on the buoy’s mooring line from three separate locations around the area where the anchor was dropped. This determines the distance from the ship to the anchor — or, more accurately, the distance from the ship to the acoustic releases. When all three distances are plotted (see the map above), the exact location of the buoy’s anchor can be determined. Success! The buoy’s anchor is 177.7 meters away from the target location — closer to the intended target than any other WHOTS deployment has gotten.

After deployment on Thursday, and all day Friday, the Hi’ialakai stayed “on station” about a quarter of a nautical mile downwind of the WHOTS-14 buoy, in order to verify that the instruments on the buoy were making accurate measurements. Because both meteorological and oceanographic measurements are being made, the buoy’s data must be verified by two different methods.

Weather data from the buoy (air temperature, relative humidity, wind speed, etc.) is verified using measurements from the Hi’ialakai’s own weather station and a separate set of instruments from NOAA’s Environmental Sciences Research Laboratory. This process is relatively simple, only requiring a few quick mouse clicks (to download the data), a flashdrive (to transfer the data), and a “please” and “thank you”.

blog.4.Day6.image2 — July 28, 2017, 5:58PM HAST. Preparing the rosette for a CDT cast. Notice that the grey sampling bottles are open. If you look closely, you can see clear plastic “wire” running from the top of the sampling bottles to the center of the rosette. The wires are fastened on hooks which, when triggered by the computer in the lab, flip up, releasing the wire and closing the sampling bottle.

Salinity, temperature and depth measurements (from the MicroCats on the mooring line), on the other hand, are much more difficult to verify. In order to get the necessary “in situ” oceanographic data (from measurements made close to the buoy), the water must be sampled directly. This is done buy doing something called a CTD cast — in this case, a specific type called a yo-yo.

The contraption in the picture to the left is called a rosette. It consists of a PCV pipe frame, several grey sampling bottles around the outside of the frame, and multiple sets of instruments in the center (one primary and one backup) for each measurement being made.

blog.4.Day6.image3 — July 28, 2017, 6:21PM HAST. On station at WHOTS-14, about halfway through a CDT cast (which typically take an hour). The cable that raises and lowers the rosette is running through the pulley in the upper right hand corner of the photo. The buoy is just visible in the distance, under the yellow arm.

The rosette is hooked to a stainless steel cable, hoisted over the side of the ship, and lowered into the water. Cable is cast (run out) until the rosette reaches a certain depth — which can be anything, really, depending on what measurements need to be made. For most of the verification measurements, this depth has been 250 meters. Then, the rosette is hauled up to the surface. And lowered back down. And raised up to the surface. And lowered back down. It’s easy to see why it’s called a yo-yo! (CDT casts that go deeper — thousands of meters instead of hundreds — only go down and up once.)

For the verification process, the rosette is raised and lowered five times, with the instruments continuously measuring temperature, salinity and depth. On the final trip back to the surface, the sampling bottles are closed remotely, one at a time, at specific depths, by a computer in the ship’s lab. (The sampling depths are determined during the cast, by identifying points of interest in the data. Typically, water is sampled at the lowest point of the cast and five meters below the surface, as well as where the salinity and oxygen content of the water is at its lowest.) Then, the rosette is hauled back on board, and water from the sampling bottles is emptied into smaller glass bottles, to be taken back to shore and more closely analyzed.

On this research cruise, the yo-yos are being done by scientists and student researchers from the University of Hawaii, who routinely work at the ALOHA site (where the WHOTS buoys are anchored). The yoyos are done at regular intervals throughout the day, with the first cast beginning at about 6AM HAST and the final one wrapping up at about midnight.

blog.4.Day6.image4 — July 29, 2017, 9:43AM HAST. On station at WHOTS-13. One CDT cast has already been completed; another is scheduled to begin in about 15 minutes.

After the final yo-yo was complete at the WHOTS-14 buoy early Saturday morning, the Hi’ialakai traveled to the WHOTS-13 buoy. Today and tomorrow (Sunday), more in situ meteorological and oceanographic verification measurements will be made at the WHOTS-13 site. All of this — the meteorological measurements, the yo-yos, the days rocking back and forth on the ocean swell — must happen in order to make sure that the data being recorded is consistent from one buoy to the next. If this is the case, then it’s a good bet that any trends or changes in the data are real — caused by the environmental conditions — rather than differences in the instruments themselves.

Personal Log:

blog.4.Day6.image5 — The *Hi’ialakai*’s dry lab. Everyone is wearing either a sweatshirt or a jacket… are we sure this is Hawaii?

Most of the science team’s time is divided between the Hi’ialakai’s deck and the labs (there are two; one wet, and one dry). The wet lab contains stainless steel sinks, countertops, and an industrial freezer; on research cruises that focus on marine biology, samples can be stored there. Since the only samples being collected on this cruise are water, which don’t need to be frozen, the freezer was turned off before we left port, and turned into additional storage space. The dry lab (shown in the picture above) is essentially open office space, in use nearly 24 hours a day. The labs, like most living areas on the ship, are quite well air conditioned. It may be hot and humid outside, but inside, hoodies and hot coffee are both at a premium!

Did You Know?

The acronym “CTD” stands for conductivity, temperature and depth. But the MicroCats on the buoy mooring lines and the CTD casts are supposed to measure salinity, temperature and depth… so where does conductivity come in? It turns out that the salinity of the water can’t be measured directly — but conductivity of the water can.

When salt is dissolved into water, it breaks into ions, which have positive and negative charges. In order to determine salinity, an instrument measuring conductivity will pass a small electrical current between two electrodes (conductors), and the voltage on either side of the electrodes is measured. Ions facilitate the flow of the electrical current through the water. Therefore conductivity, with the temperature of the water taken into account, can be used to determine the salinity.

July 27, 2015August 21, 2021

Leah Johnson: Physical and Chemical Properties of Ocean Water (There’s More Here Than Just Fish!) , July 26, 2015

NOAA Teacher at Sea
Leah Johnson
Aboard NOAA Ship Pisces
July 21 – August 3, 2015

Mission: Southeast Fishery – Independent Survey
Geographical Area of Cruise: Atlantic Ocean, Southeastern U.S. Coast
Date: Sunday, July 26, 2015

Weather Data from the Bridge:
Time 12:38 PM
Latitude 34.24389
Longitude -76.6625
Water Temperature 23.75 °C
Salinity –No Data-
Air Temperature 28.6 °C
Relative Humidity 68 %
Wind Speed 12.6 knots
Wind Direction 67.01 degrees
Air Pressure 1014.8 mbar

Science and Technology Log:
The primary purpose of this cruise is to survey reef fish. Our main task is to collect data pertaining to presence and number of fish species, species length frequency, and sample materials for fish age and growth. However, other types of measurements are being made as well. For example, the CTD is an instrument that measures different properties of ocean water with depth. It is deployed every time the fish traps are dropped.

The CTD sits on the starboard side of the deck of NOAA Ship Pisces.

The acronym “CTD” stand for conductivity, temperature, and depth. The instruments that measure these properties are affixed to a metal cylinder called a rosette. A range of sensors can be attached depending on what needs to be measured. Additionally, containers can be attached to the frame in order to collect sea water samples at different depths. When the ship reaches the designated coordinates, the survey technician calls to the deckhands and instructs them to use the winch to lower the CTD to a designated depth, and then haul it back up.

Deckhands assist with lowering the CTD.

Below you can see a graph of the data collected earlier in the week:

CTD Data

The y-axis represents depth in meters. The CTD actually measures water pressure, which is then converted to depth. Pressure and depth are directly related: as depth increases, pressure increases.

There are several different properties represented on the x-axes, shown in different colors:

light green = oxygen (mg/l)
orange = conductivity (S/m)
dark green = temperature (°C)
purple = salinity (PSU, or ppt)

What do these measurements mean? As depth increases, temperature decreases. Sunlight warms the sea surface, and wind and ocean currents distribute this heat energy throughout the upper waters. Beneath this mixed layer, temperature decreases steadily with depth. In deeper water (not at this location), this rate of change decreases and the temperature of deep ocean water is nearly a constant 3 °C. Salinity refers to the concentration of dissolved salts in the water. Average ocean salinity is 35 ppt (parts per thousand), though this varies by a few parts per thousand near the surface. Increased precipitation, runoff, or melting of sea ice can decrease salinity, and evaporation and ice formation can increase salinity. Conductivity (measured in Siemens per meter) is a measure of how much current can travel through the water, and this is affected by both salinity and temperature. Finally, fish and other marine organisms require dissolved oxygen to breathe. By measuring the amount of oxygen at different levels in the water column, we can determine how much sea life can be supported in a given area. Dissolved oxygen in the ocean comes from mixing at the surface, and is also produced by photosynthetic organisms. As temperature and salinity increase, dissolved oxygen levels decrease. Additionally, temperature and salinity data can be used to determine the water density, or the mass of water per unit volume. Different fish can tolerate certain ranges of all of these chemical and physical parameters.

With respect to the fish survey, this information is important because we can monitor the conditions of the water near the ocean floor where the traps are located. For scientists who are interested in characterizing reef fish habitat, this data is a critical component of their research.

There are other ways in which this data can be used. The depth profiles of each of the chemical and physical properties at a given site can be compared to other local sites in order to identify any spatial anomalies. This is of great interest for seafloor mapping and ocean exploration cruises. For example, a change in conductivity and temperature at a site in the middle of the ocean could indicate the presence of a hydrothermal vent. Or, a decrease in salinity in a region along a coastline could indicate freshwater runoff.

Additionally, as measurements are made at similar locations over a period of time, temporal changes may be observed. This could reveal seasonal changes, or a long-term trend. Because we are observing an increase in average global temperatures and experiencing global climate change, it is critical to collect data that can be used to assess changing ocean conditions.

Personal Log:
“Will you be eating a lot of fish on the ship?” I heard this question a lot before I left for this cruise. I wondered myself. It seemed reasonable that fish would be prepared for meals because, well, we will be living at sea! On the other hand, I wondered if everyone on board would be sick to death of fish because we would be looking at them all day. As it turns out, fish is prepared for nearly every meal; however, there is often another meat option, as well as a variety of other non-meat dishes. Now we know!

Ship mess

Did You Know?
There are many fish that make a grunting sound. When we have tubs full of tomtates in the wet lab, it sounds like a bunch of miniature pigs making snorting noises!

Still from video of tomtates near a trap. A nurse shark can be seen in the background.

April 8, 2015August 21, 2021

Theresa Paulsen: Where There is a Will, There is a Way! April 1, 2015

NOAA Teacher at Sea
Theresa Paulsen
Aboard NOAA Ship Okeanos Explorer
March 16-April 3rd

Mission: Caribbean Exploration (Mapping)
Geographical Area of Cruise: Puerto Rico Trench
Date: April 1, 2015

Weather Data from the Bridge: Partly Cloudy, 26˚C, waves 1-3ft, swells 3-6ft.

Science and Technology Log:

Dr. Wilford (Bill) Schmidt has demonstrated the saying, “Where there is a will, there is a way,” throughout this entire cruise. He knew this voyage would put his new free vehicle design to the test and he came prepared to modify this, tweak that, collaborate with the crew, confer with his university team, test, and repeat. He is an engineer and that is the name of the game.

1. The first deployment looked great. The vehicle reached 1000m. The magnetometer and 3-axis accelerometer worked great. All systems were a go. A water sampling device was used as a dummy payload.

FV Dummy Test — The free vehicle with a water sampling device as a dummy payload.

Test Data — Data from the Test Deployment

Crossing fingers for more success.

2. The next step was to attach a CTD (a probe that measures Conductivity, Temperature, Depth). The deployment and retrieval process again went smoothly, this time to 2126m, but there was a problem retrieving the log file from the bottom sphere and one of the anchor burn wires did not burn.

FV with CTD — The free vehicle with CTD attached.

Collaboration required with folks on shore and the electronics technicians on this ship. Tweak this, fix that.

Troubleshooting — Dave Blessing, Electronics Tech, and Bill Schmidt troubleshooting.

Bill opened the spheres to change the batteries for the satellite transponder.

Keeping a log — Zamara Fuentes keeping a log of all of the adjustments and parameters

Repressurizing the sphere — Rolf Vieten pressurizing the sphere

All systems were a go again.

3. The crew deployed the free vehicle with the CTD to 4679 m. It took a little longer to find and retrieve the vehicle.

FV Retrieval — Retrieval of the free vehicle

The data files indicated that the galvanic releases released the anchor prematurely, at about 100 meters from the bottom. Both spheres worked during the mission. Data files were retrieved from each. During inspection water was found in the bottom sphere. Spalling of the glass (flaking) was seen on the inside. The leak is assumed to have taken place as the surface under low pressure conditions, otherwise the damage would have been worse. The electronics were in good shape but the bottom sphere had to be retired.

Oh no! Is that the end? Not when you have great minds on board!

This is where engineering in the ocean environment gets tricky. Bill can’t just head back to the university and make the necessary repairs. Instead he needs to make use of the very valuable ship time by pinch-hitting. Bill recalculated the buoyant force on the vehicle with only one sphere. It might just work!

Tweak this, lighten that, new attachments there. Ready for a float test!

Single sphere float test — The single sphere float test was a success!

Will the single sphere allow it to ascend from the bottom fast enough for us to deploy and retrieve it during our mission? That question required further testing. So the crew planned to lower it into the water a short distance with the winch and allow it to float back up. The weather would not allow it. The seas were too rough to allow the ship to stay in one place during the vehicle test without dragging the free vehicle thereby negating the results of the test.

Plan B? The operations team hatched a plan to tie the free vehicle to buoys on a long rope. That allowed the vehicle to sink and be recovered easily if it rose too slowly. First a buoyancy test had to be done to make sure the buoys wouldn’t sink with the vehicle.

The vehicle rose in less than 10 minutes so the team was back on track! With a few extras like flags for better visibility, the vehicle was ready to dive!

Preparing for the big dive to 8000+ meters!

4. The deployment into the trench went smoothly. The crew had that routine down pat. After 10 hours it was time for the retrieval. Everyone gathered at the bridge to try to spot it.

FV lookout — On the lookout for the free vehicle.

Free Vehicle Returns — The free vehicle returns from the deep!

It successfully collected data down to the bottom at 8379m, a possible record for a free vehicle!

Successful Dive — Bill content with a successful dive

The CTD data was processed and looked great during the descent.

FV CTD data — Free vehicle CTD data from the Puerto Rico Trench

Inspection of the data log showed that while the vehicle was ascending from the bottom, something was triggering a mission cancel order – 28 times! This bug required more testing and mission simulating before another deployment in the trench. Just after 8pm, Bill announced his equipment was ready to go for a 6 am deployment the next day.

5. The next day, the retrieval took a bit longer due to choppier sea conditions.

The crew bringing the free vehicle aboard.

Again the vehicle logs showed “cancel mission” messages during the ascent. It is confounding Bill and his team back home, because during mission simulations the mission goes to completion without a problem.

In all the voyage has been very constructive for Bill’s engineering team. They successfully deployed the vehicle to the bottom of the Puerto Rico Trench known to be the deepest part of the Atlantic Ocean. That is something to celebrate! They have learned a great deal about what types of modifications they should make to improve the retrieval process.

This was a great first test of the free vehicle design. The next time out at sea will come soon enough and Bill’s team will be ready!

Personal Log

As the voyage comes to an end and we travel nearer to shore, I am filled with mixed emotions. I will miss the ocean, the feeling of being a part of an exploration expedition, and these people. I am also very happy to be going home to my family and my students. I am looking forward to sharing what I have learned. I will be looking for partnerships to help get students involved in reseach on our inland sea, Lake Superior. If you have any suggestions, please leave a comment below!

Exciting moments? Seeing these creatures!

Whale — Small whale swimming next to the vessel.

Dolphin — A dolphin playing in our wake. Photo credit: Jossue Millan

Other great moments include driving the ship and making video fly-bys of the ocean floor with the bathymetry and backscatter data. Very awesome! The videos will be coming soon so stay tuned!

Did you know?

Do you remember the flying fish I wondered about a few blogs ago? I have never seen them before. At first I thought I was seeing things. I thought I saw a very large dragonfly dive into the water. Then I saw more. – schools of them jumping away from the boat all at once. In a blink of an eye they were gone.

A flying fish. Image courtesy of “Bermuda: Search for Deep Water Caves 2009 Exploration,” NOAA Ocean Explorer

According to Wikipedia, there are 64 species of flying fish! They fly out of the water to evade predators. That’s a pretty cool adaptation! You can learn more here.

Question of the Day: