Alaska Sea Grant
  • Home
  • NGSS-Aligned Investigations
Submersibles: Doing Science You Cannot See
This series of investigations first introduces students to different types of submersible robots that can be used in underwater science. They will do a simulation of an activity (in their gym) that one type of robot – “Buttercup,” a remote operated vehicle or ROV “tethered” to people operating it on the surface – performs in Kachemak Bay, Alaska to count rockfish on a linear transect. Students will then assemble ROVs using PVC pipe, pipe insulation, and motors, and test its buoyancy and their ability to control its direction in a large water container like a clean “fish tote.” Students then practice with their ROVs at a local pool and carry out one or more of the challenges or missions suggested in the investigation (such as engineering a device, such as a scoop or a net on their robot so that they are able to retrieve something). If waterproof cameras are available, students can add these to their ROV and carry out other types of missions. The culminating activity is a project that students design to collect observations and/or data in the local aquatic or marine environment.
Essential Question(s)
How can we choose which technological tools (hardware and software) to use for specific tasks?
How could submersibles be used (or are they currently used) to study our local aquatic or coastal environment?
PDF Investigation
Time Required
10 60-min. sessions
Technology/ Engineering
Investigation Type
Field Trip, Classroom, Technology
Grade Level
Middle School
NGSS Performance Expectations
Materials Needed

Submersibles PowerPoint

Scooter Boards
Meter sticks
80 paper fish approx. 15 in. long
Robotics equipment: PVC pipe, connectors, motors and Controllers, electrical tape, pipe insulation, zip ties, 12-volt batteries, and chargers
1 Fish Tote
1 rubber tote for each ROV and other materials
Timers (for missions)

Underwater cameras

NGSS Performance Expectation

Students who demonstrate understanding can:

Apply Newton’s Third Law to design a solution to a problem involving the motion of two colliding objects. (MS-PS2-1)

Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object. (MS-PS2-2)

Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions. (MS-ETS1-1)

Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved. (MS-ETS1-4


Knowledge - Students will know that:
  • there are advantages and constraints on using a submersible to collect environmental observations and data.
Skills - Students will be able to:
  • to work as a team and solve problems.
  • design a scientific investigation and collect scientific data about their local environment.
  • to determine the appropriate use of submersible technology.
Local and Cultural Connections
Encourage students to talk to local experts, agency personnel, Elders, and other long-term local residents before designing a study using submersibles. Is there something related to the ocean or aquatic environment that is of concern to the community and would best be studied by underwater robots? Who can use the data the students could collect? Is this issue something that could be monitored or studied safely and efficiently using a submersible?
Teacher Preparation

This investigation depends on the acquisition or use of robotics equipment. (See the MATE vendor information in the Resources section.) The motors and the controllers are available on loan for the cost of the shipping. You can fill out an online request form on the MATE website.

You will still need to get the PVC pipe, connectors, pipe insulation, batteries and chargers, electrical tape, and zip ties, but a school site council or our PTA may be able to help. Arrange for a loan of a fish tote to have at school temporarily; ask the custodian for the best place to place this. You can also collect miscellaneous equipment for attachments such as scoops, sand shovels, net, and kitchen utensils.

Cameras and recorders provide more options for challenges and activities if these are available for the students to use. You may be able to purchase a monitor and waterproof video that works well for under $200 or you be able to borrow one from a local agency such as NOAA or the Alaska Department of Fish and Game.

Secure permission to us a local pool and scout out field trip sites for the student projects. Arrange necessary permissions, transportation, adult volunteers, and other logistics.

Session 1: Review the Introduction to Submersibles PowerPoint presentation with 10 slides designed to get students started with their own research about ROVs and AUVs. The last slide gives students instructions to search on their own to find out more.

Print out the Boats of the Week newspaper article (See Resources section for link) and make copies if you plan to have students read it on their own.

Session 2: Transect Activity.  Read through the  ROV Exercise: Surveying Rockfish Simulation for a detailed description of how this activity was done in McNeil Canyon Elementary School in Homer, Alaska. Review the McNeil Transect Data on Excel spreadsheets (there are several layers different sheets) for an example of data collection and analysis. ((See Resources section for downloadable files.) 

This activity is designed to take place in the school gym or multi-purpose room. Divide the gym into 1-meter long sections and set up boundaries for a rectangular area. If you use the measurements in the McNeil Canyon Elementary Example - 21 meters by 13 meters, the math equations can also work as an example.

Spread out previously cut out 80 paper fish about 15 inches in length randomly around the gym flat on the floor, across the meter long sections.

Gather scooter boards and meter sticks.

All pool sessions:  Move the necessary supplies and equipment to the pool ahead of time. If possible, ask parent volunteers to set everything up. One or more will need to go into the water to retrieve ROVs or other materials.

Pool sessions when students carry out missions:  Review the suggested missions ahead of time and decide which ones you will assign and what specific materials will be needed for the practice session and the actual, scored mission. Arrange for judges to score the missions and invite parents and the local media. This is a fun and exciting event!

Learning Experiences

Session 1


(60 mins.)

  1. Ask students: How we might study science in places we can’t see? Students might have some ideas and might even come up with sending robots and probes technology to outer space and to the deep sea.
  1. PowerPoint presentation: Introduction to Submersibles
    - Show students the pictures of robots past and present that have served this purpose explaining that you are going to focus on the variety of  ways that scientists have used technology to explore and collect data from the ocean, including some currently being used like the sea gliders that are currently being used to study the CO2 levels in the ocean.

    -  Explain that an ROV used in Kachemak Bay to survey rockfish populations has been named “Buttercup.” To do the surveys, people fly the ROV along lines called transects. The robot calculates the number of fish its camera “sees” in a certain-sized area, then uses that calculation of density (no. of animals/unit of area) to estimate how many fish would be in a rockfish population over a larger area of rockfish habitat.

    Buttercup also had a moment of fame when it helped out a NOAA ship rescue a very expensive piece of equipment. You could pause the presentation and have students read the newspaper story or read it to them. Discuss how this ROV was able to retrieve a very expensive piece of equipment with the mechanical ingenuity of a local fisherman and the skilled ROV technician.

    - Continue the PowerPoint presentation and then allow students to do their Internet search and share their findings. 

Extension: If you have the ability to print out some images along with their information, these would make a great display for this unit. 

Session 2

EXPLORE:  Transect Activity

(40 mins.)

  1. After you have laid out your one-meter-wide sections on the gym floor, divide the students into pairs and ask each pair to choose a number between 1 and 21. Each pair will need to get a scooter board and a meter stick and then go to that number on one end of the floor to begin what will be their transect.

  2. To move along the transect, one student will sit on his or her knees on the scooter board and hold the meter stick in the middle so that the meter stick is sticking out half-way on each side of the scooter board. The other student will gently and slowly push the student on the scooter board down the transect line as if that student is Buttercup looking for rockfish. Buttercup can only count a fish if it sees more than half the fish, so if a student sees less than half the fish, he or she may not count it. The pair counts fish along their transect. When they reach the end of the transect, they reverse roles, go in the opposite direction, and repeat the count. If they get different numbers on the counts, they will average the two numbers. 
  1. After all students have completed the counts on their transects, they return to the classroom with their population survey data.


(20 minutes)

  1. Students compile their counts and divide by a multiple of 13 so total fish total (dividend), is divided by the total number of transects. (If you had 10 pairs of students then the divisor would be 130). The quotient is the density of the fish measured by the transect method.
  1. Students multiply the density of fish they just calculated by the area of the gym the fish that represents the survey areas (i.e., 21 meters by 13 meters or 273 square meters). The result is the estimated number of fish in the entire area based on their transects run by “Buttercup.” (Or your students in this case!) Ask students to consider why more transects would provide a more accurate estimate of the abundance of rockfish. Ask them to imagine how many would be needed for an area as large as Kachemak Bay or a local bay or inlet.


Show the PowerPoint presentation Buttercup’s Great Adventure. (See Resources section.)

Session 3, 4, and possibly 5


(60 min. sessions)

  1. Give students at least two one-hour practice sessions at the fish tote testing tank. Students work in teams of 3-4 students, build their ROVs. They use three motors and fasten pipe insulation to the PVC pipe to make their ROVs neutrally buoyant and as balanced as possible. They test the buoyancy in the tank.

  2. Explain to students that during upcoming sessions at the pool. They will be assigned a mission and they will design their ROVs to accomplish that mission.

    Idea-List for Possible Underwater Missions at the Pool
    (No longer than 5 minutes each)
    1. The Flying Mission:  Using swimming pool lane boundaries, students ‘fly” the ROV down the length of the pool, cross under the lane boundary, come up the length of the pool the other direction, and return to the starting point. This is the easiest of the missions. They must keep their ROVs within the boundaries during a timed trial. (You can decide what's a reasonable amount of time for the trial.)The Hula Hoop Mission: 

    Attach a hula-hoop with a zip tie to a brick or a weighted item they have at the swimming pool. Students fly the ROV through a hula hoop forwards and then turn the R-O-V around and fly it back through it. Another variation is for students to fly the ROV backward through the hula-hoop. A parent or student volunteer is needed to help with setting up the course and occasionally freeing angled ROV and filming underwater.

    2.  Retrievable Mission: Throw 4-6 ping pong balls into the pool to simulate an oil spill or a group of something that needs plucked from the ocean. Students fly the ROV to retrieve the ping pong balls and bring them to the side of the pool where they can retrieve them from the submersible. This can be done in several trips, as long as the time permits, (usually 3 -5 minutes)

    3. The Push Mission: This mission requires the submersible to push a ball has weights attached but which is as neutrally-buoyant as possible to the side of the pool where one of the team members can reach in and grab the ball, again within the time limit. 

    4.  The Hook Mission: 
    The ROV must retrieve something lying at the bottom of the shallow end of the pool that must be hooked and brought to the side of the pool where a team member may grab it, within the time limit.

    The addition of underwater cameras to the ROVs is especially fun and useful if the students are going to be able to use the ROVs in the local environment. Even if there are only a couple of set-ups to share, it is really powerful to see how that transmits the image of the real world for observation and research back and especially from something that they built themselves. The next two missions require a camera:
    5.  The Secret Message Mission:  The ROV must dive down and read a message written on a mirror on the bottom of the pool. (This is down by flying the camera so it points at the message and it can be read topside by the pilot.)

    6.  The Fly-by-Night Mission: 
    This mission is accomplished by only using the field of vision on the camera to capture another hook mission. It works best if the device to capture the hook is visible from the camera view. 

Session 5 or 6


Practice sessions for missions with ROVs at a local pool

(60 mins.)

  1. Each student teams takes their ROVs and extra supplies for adjusting designs and repairing ROVs along with charged batteries and one extra charged battery. Explain the missions at poolside and allow practice time. (Have parent volunteers go ahead of time and set up missions – students do not get into the pool. Parent volunteers stay to help in water as needed with getting ROVs unstuck or setting up missions again.
  1. Explain “flying in three dimensions.” Everyone on the team takes turns piloting and making adjustments in design.

       It’s a bonus if you can work with agency personnel for this activity. Alaska Department of Fish and Game or NOAA personnel are ideal and it's even better if they have been involved earlier in the unit.  Extra expertise is extra exposure for your students!

Session 6 or 7


Carrying out the Missions
(2 – 3 hours, have at least 2 courses set-up so 2 teams can go at a time.)

Ask parent volunteers set up the mission ahead of time and stay in the pool for help when needed and for filming underwater. Have one parent take photos topside so you will have plenty of photos for a display after the unit. Use agency personnel and local experts as judges for this day if at possible.

Session 7 or 8: Plan a Project
(60 mins.)

After the de-brief of the mission (see below), students design a study, monitoring project or citizen science project using a submersible. The goal is to use it as a tool to monitor something that is useful to study to add to the knowledge base of science and something that is useful in understanding or solving a problem in the local environment. Students need to consider constraints on the operation of a submersible to cause as little disruption to a local marine or aquatic ecosystem as possible.

If possible, invite government agency personnel or local experts to talk to your class to get an idea of a need or a project that might be possible to do using student robots in your local area. (Or talk to them if they can’t get away - is there current research that is going on in the local area that can give the students ideas about what they can do using their technology as an exploration tool for learning?

Brainstorm and discuss with the class, come up with ideas. Describe what they could do with their robot to modify it for use or research task in the local environment. What would be an issue – for example is buoyancy affected by the salt in the ocean water? What adjustments might be necessary?

After a possible robot modification session in class, take the class to local environment with the robots. (Students may have come up with some ideas on what they could do with their robots and projects with the local environment, but if they haven’t yet, that is all right. Ideas may come later, but first, they may need more experience and exposure with this tool for this purpose.) If robots are outfitted with cameras or video cameras, plan on taking some pictures and or video footage in the local environment and analyze the images later. Can the students identify living organisms or other items in the local environment? What is the visibility like? Is there a difference between what the different robot’s encounters in the local environment? Is it different than the students see from the surface?


After any further student research extensions are explored, dismantle robots, return borrowed equipment, and make a photo display board of students involved in this project. This is an exciting opportunity to inspire others as well as encourage your students to continue this venture into the world of underwater technology and exploration.


Scoring options for missions:
Students score for points on a scale of 1 – 5 for each mission with partial points possible.
Students score 1 point for completion and no point for incomplete mission.

Formative Assessment - Mission Debrief Session:
(60 minutes)

After the final pool session, students debrief back in the classroom. They reflect on the experience and their submersible design. What worked well and what needed more engineering if they had more time and could make some recommendations? 

Summative Assessment:
Assess the students’ project planning skills. If they are not able to carry out their project, assess their performance of skills in developing questions and designing the investigation that makes appropriate use of the technology.

Assess teamwork and participation in individual and group discussion.

Introduction to Submersibles PowerPoint

Introduces students to submersibles and their uses in marine research and citizen science

Introduction to Submersibles PowerPoint

Introduces students to submersibles and their uses in marine research and citizen science

Boats of the Week

Article about the ROV Buttercup retrieving scientific equipment from the seafloor in Kachemak Bay

ROV Exercise: Surveying Rockfish Simulation

Description of an ROV activity as it was done in the McNeil Canyon Elementary School in Homer, Alaska. Grades 4-8.

ROV Transect Sampling

Excel spreadsheets with transect sampling form and data from a simulation at McNeil Canyon Elementary School, Homer, Alaska

Teacher Background

This investigation was developed by Sheryl Sotelo for Chugach School District after the District purchased a submersible with funds provided by Alaska Sea Grant through their school grant program.  

A lot of preparation and gathering of materials is required for this unit, but it is a powerful and engaging unit and worth the effort.

Prior Student Knowledge: Students should understand the concepts of buoyancy and neutral buoyancy.

Components of Next Generation Science Standards Addressed

Science & Engineering Practices

Constructing Explanations and Designing Solutions
Apply scientific ideas or principles to design an object, tool, process or system. (MS-PS2-1)

Planning and Carrying Out Investigations
Plan an investigation individually and collaboratively, and in the design: identify independent and dependent variables and controls, what tools are needed to do the gathering, how measurements will be recorded, and how many data are needed to support a claim. (MS-PS2-2)



Asking Questions and Defining Problems

Define a design problem that can be solved through the development of an object, tool, process or system and includes multiple criteria and constraints, including scientific knowledge that may limit possible solutions. (MS-ETS1-1)

Developing and Using Models
Develop a model to generate data to test ideas about designed systems, including those representing inputs and outputs. (MS-ETS1-4)

Disciplinary Core Ideas

Disciplinary Core Ideas

Forces and Motion
For any pair of interacting objects, the force exerted by the first object on the second object is equal in strength to the force that the second object exerts on the first, but in the opposite direction (Newton’s third law). (MS-PS2-1)

The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force needed to achieve the same change in

motion. For any given object, a larger force causes a larger change in motion. (MS-PS2-2)

ETS1.A:  Defining and Delimiting Engineering Problems

The more precisely a design task’s criteria and constraints can be defined, the more likely it is that the designed solution will be successful. Specification of constraints includes consideration of scientific principles and other relevant knowledge that is likely to limit possible solutions. (MS-ETS1-1)

ETS1.B: Developing Possible Solutions

A solution needs to be tested and then modified on the basis of the test results, in order to improve it.
Models of all kinds are important for testing solutions. (MS-ETS1-4)

ETS1.C: Optimizing the Design Solution 

The iterative process of testing the most promising solutions and modifying what is proposed on the basis of the test results leads to greater refinement and ultimately to an optimal solution. (MS-ETS1-4)

Cross-Cutting Concepts

Systems and System Models

Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy and matter flows within systems. (MS-PS2-1)


Stability and Change

Explanations of stability and change in natural or designed systems can be

constructed by examining the changes over time and forces at different scales.



Connections to Engineering, Technology, and Applications of Science

Connections to Engineering, Technology, and Applications of Science

Influence of Science, Engineering, and Technology on Society and the Natural World

The uses of technologies and any limitations on their use are driven by

individual or societal needs, desires, and values; by the findings of scientific

research; and by differences in such factors as climate, natural resources, and economic conditions. (MS-PS2-1)


The uses of technologies and any limitations on their use are driven by individual or societal needs, desires, and values; by the findings of scientific research; and by differences in such factors as climate, natural resources, and economic conditions.

All human activity draws on natural resources and has both short and long-term consequences, positive as well as negative, for the health of people and the natural environment. (MS-ETS1-1)

Common Core

WHST.6-8.8 - Gather relevant information from multiple print and digital sources, using search terms effectively; assess the credibility and accuracy of each source; and quote or paraphrase the data and conclusions of others while avoiding plagiarism and following a standard format for citation. (MS-ETS1-1)
7.EE.B.3 - Solve multi-step real-life and mathematical problems posed with positive and negative rational numbers in any form (whole numbers, fractions, and decimals), using tools strategically. Apply properties of operations to calculate with numbers in any form; convert between forms as appropriate; assess the reasonableness of answers using mental computation and estimation strategies. (MS-ETS1-1)
MP.2 - Reason abstractly and quantitatively. (MS-ETS1-1)
Alaska Cultural Standards
B. Culturally-knowledgeable students:
B.4. Identify appropriate forms of technology and anticipate the consequences of their use for improving the quality of life in the community.
Developed by Sheryl Sotelo for the Chugach School District. Adapted for Alaska Sea Grant by Marilyn Sigman, Alaska Sea Grant.
Last Updated on
Last Updated by
Marilyn Sigman
Alaska Sea Grant University of Alaska Fairbanks Alaska Department of Education and Early Development NOAA