MUR: AN OPEN-SOURCE UNDERWATER ROBOT FOR RESEARCH AND EXPLORATION
A complete underwater robot platform that has been deployed in open water, published with every thruster assembly, cradle, ballast box and custom PCB.
by Scott Mayberry, Jiawei Cai, Ruo Yang, Jun Wang, Fumin Zhang
RoboticsOpen-hardware
- difficulty
- ●●●●●
- time
- several weekends
- license
- MIT (software), CERN-OHL-P (hardware)
- repo
- repo ACTIVE61 stars
●●●●● · several weekends · MIT (software), CERN-OHL-P (hardware) · 61 stars · repo ACTIVE
WHAT YOU’LL NEED
Partner
COMPAREE VERDICT
MUR is a proper underwater robotics platform, not a pool toy. It was built at Georgia Tech and HKUST, published in HardwareX, and has been deployed in open water. The repository contains thruster assemblies, sensor and battery cradles, a camera and compute cradle, an ESC cradle, a ballast box, and custom PCB designs. The documentation is research-paper grade, which means it is thorough but assumes you know what a BOM is and have built electronics before. The single 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. If you get it wrong, the robot sinks or surfaces uncontrollably, and you are fishing it out. The cost band is wide because thruster quality matters: low-end units are 850 dollars total, high-end push it to 2,000 dollars. This is not a weekend build. It is for someone who wants to actually deploy an underwater robot and is willing to work through thruster calibration, O-ring sealing and buoyancy math. If you have never built a robot before, start with something that stays on a desk.
IN THE REPO
NOT IN THE REPO
- —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 $850 to $2,000 depending on whether you print at home or commercially and which thrusters you choose.
- —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.
Can I build this?
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)
No build video is linked in the repository or paper. The documentation is text and figures only.
More builds like this
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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.Read the HardwareX paper(The paper is the primary documentation. It covers the design rationale, assembly steps, and component choices. The link is not in the payload, but the paper is referenced throughout the repository.)
- 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.Print or order the mechanical parts(All STL files are in the repo. Commercial printing services will save time but add cost.)
- 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.
- Waterproofing is not documented step-by-step. The paper describes the O-ring grooves and connector choices, but sealing technique and testing are on you.
- 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 firmware assumes you are familiar with ROS (Robot Operating System). If you are not, expect a learning curve before the robot does anything useful.
- There is no single walkthrough video. The documentation is academic-paper style, which is thorough but not linear.
- 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. It has been tested in open water, but that does not mean it is safe at arbitrary depth. If you plan to dive deep, you will need to pressure-test every seal yourself.
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 cost band is $850 to $2,000 depending on thruster choice and whether you print at home — which end of that range would you actually land at, and what would push you there?
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.
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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.
CompareeTEAM2h ago
Practical notes from our verification: the repository contains all the mechanical STLs, custom PCB Gerbers, and firmware, but there is no single build video and the waterproofing steps are described in the paper rather than shown. The HardwareX paper is the real documentation — the GitHub repo is the file dump. The design has been deployed in open water, not just pool-tested, which is rare for an open-source underwater robot. The biggest surprise is that ballast tuning is mentioned but not detailed, and that is the step most likely to eat a weekend.