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MUR: AN OPEN-SOURCE UNDERWATER ROBOT FOR RESEARCH AND EXPLORATION

A complete underwater robot platform, tested in a water tank and published with every thruster assembly, cradle, ballast box and custom PCB.

by Scott Mayberry, Jiawei Cai, Ruo Yang, Jun Wang, Fumin Zhang

FULL CAD BOM FIRMWARE DOCS

RoboticsOpen-hardware

Built withTeensy3D printing

difficulty
●●●●●
time
several weekends
license
MIT (software), CERN-OHL-P (hardware)
repo
repo ACTIVE66 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

MUR is a proper underwater robotics platform, not a pool toy. It comes from Georgia Tech and HKUST, is published in HardwareX, and was characterised in a controlled test tank (station-keeping at different depths, power consumption and communication). The repository contains thruster assemblies, sensor and battery cradles, a camera and compute cradle, an ESC cradle, a ballast box, custom PCB designs, Teensy firmware and ROS packages, plus step-by-step assembly videos for each module. The documentation is research grade: thorough, but it assumes you have built electronics before. The hardest part is not the printing or the soldering, it is the waterproofing and ballast tuning, neither of which you can test until the robot is in water. The README prices the build from about 860 dollars (self-printed, cheaper thrusters) to about 2,040 dollars (commercially printed, T200 thrusters). This is not a weekend build. It is for someone who wants to deploy an underwater robot and is willing to work through thruster calibration, sealing and buoyancy tuning.

GOOD TO KNOW

  • —Complete mechanical CAD, custom PCB designs, firmware and assembly documentation are all present.
  • —The hardware is under CERN-OHL-P (permissive, allows commercial use) and software is MIT licensed.
  • —The paper in HardwareX documents the build in detail and the design files are on both GitHub and Zenodo.
  • —Cost is about 860 to 2,040 dollars depending on whether you print at home or commercially and whether you use T200 or other thrusters.
  • —This is research-grade hardware: waterproofing, thruster calibration and ballast tuning are all real work.
  • —No off-the-shelf kit exists — you are sourcing every component, printing every part, and assembling custom electronics.

Parts to buy

9 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • Thrusters (low or high-end)Find
  • Custom PCBs (Gerbers provided)from the repo files
  • MotorsFind
  • ESCsFind
  • SensorsFind
  • BatteryFind
  • O-ringsFind
  • Waterproof connectorsFind
  • Ballast weightsFind

Can I build this?

PrintThruster assemblies, sensor and battery cradle, camera and compute cradle, ESC cradle, ballast box. All STL files are in the repository.
BuyThrusters (low or high-end), custom PCBs (Gerbers provided), motors, ESCs, sensors, battery, O-rings, waterproof connectors, ballast weights. Full BOM is in the paper and repository.
Tools3D printer (or commercial printing service), soldering station, PCB assembly capability (or use a board house), basic hand tools, access to water for testing.
SkillsAdvanced. Requires mechanical assembly, custom PCB soldering or ordering, firmware flashing, and real waterproofing work. Ballast tuning and thruster calibration are not trivial.
TimeSeveral weekends minimum. Printing, assembly and electronics are the first half; waterproofing, ballast tuning and water testing are the second half, and that is where time disappears.
CostAbout 860 to 2,040 dollars. Thruster choice (T200 or cheaper thrusters) is the biggest factor, followed by home versus commercial printing.
SafetyLithium battery in a waterproof enclosure. If the seal fails, the battery is underwater. Test in shallow controlled water first. Real risk of losing the robot if ballast or waterproofing fails in open water.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

The Miniature Underwater Robot (MUR)

Scott Mayberry's own intro video. The repository also has assembly videos for every module (thrusters, cradles, ballast box) plus a full-assembly video in hardware/Assembly.

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Gallery

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Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the HardwareX paper(The HardwareX paper covers the design rationale, assembly steps and component choices; the repository's hardware and software READMEs and assembly videos fill in the details.)
  2. 2.Check the BOM and order components(The bill of materials is in the repository. Thruster choice (low-end or high-end) is the biggest cost decision.)
  3. 3.Print or order the mechanical parts(All STL files are in the repo. Commercial printing services will save time but add cost.)
  4. 4.Order or assemble the custom PCBs(Gerber files are provided. You can send them to a board house or assemble them yourself if you have the equipment.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • The cost range is wide and the BOM does not pick a single thruster model for you — if you order the wrong grade, you will either overspend or undershoot the performance the design expects.
  • Watch the module assembly videos closely for the sealing steps, and leak-test every enclosure in a bucket before the robot goes near open water.
  • Ballast tuning requires water access and multiple iterations. The robot will not float correctly on the first try, and you cannot tune it on a bench.
  • The software stack is a set of ROS packages (control, sensors, model and a launcher). If you are new to ROS, expect a learning curve before the robot does anything useful.
  • The documentation is spread across the paper and several README files; use the per-module assembly videos in hardware/Assembly to keep your place.
  • If you lose the robot in open water due to ballast or control failure, there is no backup plan in the docs. Test in controlled shallow water first.

Can I use different thrusters?

The design accommodates a range of thrusters, but you will need to adjust the mounting and possibly the ESC ratings. The BOM lists options, but mixing models without recalculating thrust and power draw is a fast way to end up with a robot that cannot hold position.

Do I need to know ROS?

Yes. The software stack is built on ROS, and the firmware expects you to configure nodes and topics. If you have never used ROS, budget time to learn it before you try to run the robot.

How deep can it dive?

The paper does not specify a rated depth, and the design is not certified for deep water. The published tests were done in a controlled water tank, with WiFi and Ethernet tethering aimed at shallow water. If you plan to go deeper or into open water, pressure-test every seal yourself first.

Can I use this commercially?

Yes. The hardware is CERN-OHL-P (permissive) and the software is MIT, both of which allow commercial use.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

The README prices the build from about 860 dollars (self-printed, cheaper thrusters) to about 2,040 dollars (commercially printed, T200 thrusters). Which end of that range would you land at, and what would push you there?

CompareeTEAM1mo agoedited

Practical notes from our verification: the repository contains the mechanical files, custom PCB Gerbers with pick-and-place files, Teensy firmware, ROS packages and a full BOM spreadsheet, and it is more than a file dump: hardware/Assembly has step-by-step assembly videos for the thrusters, ballast box, ESC and sensor cradles, camera and compute module, and the full robot. The HardwareX paper adds the background and testing. The README links an intro video and an example deployments video. Software is MIT and hardware CERN-OHL-P. The biggest time sink is likely the waterproofing and leak checks, so use the leak detectors the design includes before the first dive. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

Scott Mayberry, Jiawei Cai, Ruo Yang, Jun Wang, Fumin Zhang

The team is from Georgia Tech and the Hong Kong University of Science and Technology. They published MUR in HardwareX, a journal for open-source scientific hardware, to make underwater robotics accessible for research and education.

GitHub

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
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