Overview

This vertical profiler was designed for the 2026 MATE ROV International Competition at the Fisheries and Marine Institute of Memorial University in Newfoundland and Labrador, Canada. The competition environment included an ice tank rated to -25°C, which became one of the main design challenges.

We developed a vertical profiler rated for 5 m depth and -30°C operation, with a material cost of less than $200 USD.

I led this project and found that management, especially engineering project management, is something I want to explore further as a career. This project gave me the opportunity to grow my skills in planning, project management, technical decision-making, and working with a team of engineers.

Goals and Design Requirements

The requirements for this project were fairly simple at first. We had to meet the MATE ROV safety requirements, the environmental requirements from the competition pool, and a few additional requirements that we set for ourselves. The project also had an overall budget of $500 USD.

Requirements:

• Rated for at least 3 m depth

• Rated for -25°C operation

• Chemically resistant to glycol-based antifreeze

• Transparent housing

• Professional appearance

• Meets MATE ROV safety guidelines

  • Pressure relief valve
  • Battery and power regulations

• Meets vertical profiling requirements for scoring points

• Built within a $500 USD budget

Design Philosophy

Our design philosophy is based on asking “why” before committing to a solution. We start by defining the main goal, then turn that goal into minimum viable design requirements. Those requirements describe what the system must do, not how it must be built.

That distinction is important. When solutions are written into the requirements too early, the team can get locked into an approach that may not be the best fit. By keeping the requirements focused on the problem, we leave room to compare multiple solutions through sketches, calculations, trade studies, and testing.

The first step is always defining the problem statement or main goal. In this case, the goal was to develop a vertical profiler to compete at the MATE ROV competition. From there, we identify what must be true for that goal to be met. These become the minimum viable product design requirements. They are the requirements that must be met for the project to be successful.

After that, we can also define a second set of more ambitious goals. These goals may improve the design, but they are not required to meet the main objective.

One thing I have seen many peers do is accidentally put solutions into their design requirements. This can back a project into a corner and force a solution that may not be optimal for the application. Making sure that design requirements only state what needs to be done is extremely important.

Once the team knows what must be done to meet the goal, we can start deciding how to meet those requirements. I like to do this with a Work Breakdown Structure, or WBS. This helps create a project timeline by breaking the project into tasks and subsystems that can be assigned to team members. From the WBS, we can also create deadlines for each task.

Within those tasks, we can divide the overall budget based on predictions for what each subsystem will cost. This allows us to assign a budget to each task along with the technical responsibility.

Another tool that I have found useful is an Interface Control Document. As a team, we decide how each subsystem will interface with the others. This lets us create standards for how everything will fit together. When team members come back with their individual parts, the final integration is much smoother.

That is the basic design process that I like to use. I also like to require a weighted decision matrix or trade study for major design decisions. This encourages the team to look at many possible solutions and carefully consider each decision before committing to a design.

Another important part of my design philosophy is always returning to the main goal. If a feature does not help meet the main goal, then there is usually no reason to add it. I also encourage answering “why” with mathematical proof when possible. Numbers are objective, and they can help show which solution is best.

Mechanical Design

The enclosure is made from machined transparent PVC. We chose this material because transparent PVC has a glass transition temperature around -30°C and excellent chemical resistance against glycol-based antifreeze.

One of the main challenges with this part was thermal expansion and contraction across a wide temperature range. We decided to make the entire enclosure out of PVC to reduce material mismatch problems. We calculated O-ring shrinkage and compression to make sure the enclosure would remain watertight from room temperature down to the rated -30°C operating condition.

We were fortunate to have a machinist on our team who was able to machine two prototypes for us. It was also useful to experience the relationship between engineer and machinist and learn how to create designs that are practical to machine.

Buoyancy Engine

The buoyancy engine is built from a 100 mL syringe actuated by a 9 g hobby servo through a rack-and-pinion gear system. This proved to be a very cost-effective solution while giving us more performance than required. It pushed the rated depth of the vertical profiler down to 5 m while only pulling about 500 mA at stall current.

Electronics

The electronics are fairly simple. A board-level integration PCB at the top of the internal structure houses almost all of the necessary electronics.

The microcontroller chosen was the ESP32-C3 because of its performance, IoT capability, and SparkFun’s integration of the chip onto their Pro Micro-style board. This gave us an extremely small form factor that fit within the limited PCB space.

We also decided not to use an external antenna and instead required the housing to be RF transparent. This helped reduce complexity in the overall design. In addition to the microcontroller, the electronics include a logic-level shifter, RTC, LED array, and buck converter, all placed within a 65 mm circular PCB area.

Software and Controls

The software is where we decided to add the most features. Because of the Wi-Fi capabilities of the ESP32-C3, we run the profiler in Wi-Fi access point mode. This allows any electronic device to connect directly to the profiler and eliminated the need to develop separate hardware for a base station.

The interface includes options for starting and stopping the profile, telemetry output, a depth-over-time graph required by the competition, PID controls, profile and mission controls, and a manual control mode.

These features mean that we do not have to flash code or open the enclosure for minor changes or tuning. This increases ease of use and creates a more accessible product.

Software repository:

View the Vertical Profiler 2026 GitHub repo

Problems and Revisions

There were many problems and issues during the development and testing of the first prototype. The biggest issue was the buoyancy engine.

The original design used an expensive Actuonix actuator that bound up and did not reach the calculated depth performance. This happened because we rushed the buoyancy engine design and did not complete a proper trade study on multiple possible designs. That led us to a poor design choice.

After going back and completing the trade study properly, we selected the rack-and-pinion syringe design used in the current prototype.

Another problem we faced was the control algorithm. Small ballast errors made it easy for the profiler to oscillate around the wrong depth. Even an error as small as 0.2 g could affect how the profiler behaved. To address this, we developed and tested different control algorithms using the vertical profiler simulator.

View the Vertical Profiler Simulator page

Final Result

In the end, we were able to produce two prototypes within our budget. Both prototypes are capable of competing at the MATE ROV competition. Through the design process, we were also able to complete both prototypes on time.

Then it was time for competition. Once we fixed the major problems, we had an extremely capable device that we were confident would perform well. We set the buoyancy, prepared for the product demonstration, and completed the run successfully. Everything went smoothly, and we scored the full 85 points with no major issues.

Through proper design philosophy, careful planning, and a willingness to slow down before acting quickly, we were able to create a highly capable machine.

Supporting Documents

The full Google Drive project folder includes additional documentation, CAD files, PCB schematics, reports, and project files.

View the full VP 2026 Google Drive folder