Skip to content

Southern Fried Science

Over 15 years of ocean science and conservation online

  • Home
  • About SFS
  • Authors
  • Support SFS

The next generation of low-cost, open-source oceanographic instruments is here! Meet the OpenCTD rev 2!

Posted on January 7, 2020January 7, 2020 By Andrew Thaler 1 Comment on The next generation of low-cost, open-source oceanographic instruments is here! Meet the OpenCTD rev 2!
Oceanography for Everyone, Open Science, Science
Four generations of OpenCTD. Left to Right: Prototype 2, which went through sea trials in Lake Superior, rev 1, rev 1 in the smaller form factor (this one was deployed in Alaska), and OpenCTD rev 2.

In 2013, Kersey Sturdivant and I embarked upon a quixotic quest to create an open-source CTD — the core tool of all oceanographic research that measures the baseline parameters of salinity, temperature, and depth. We weren’t engineers; neither of us had any formal training in electronics or sensing. And, full confession, we weren’t (and still aren’t) even oceanographers! What we were were post-doc marine ecologists working with tight budgets who saw a desperate need among our peers and colleagues for low-cost alternatives to insurmountably expensive equipment. And we had ties to the growing Maker and DIY electronics movements: Kersey through his work developing Wormcam and me through my involvement with OpenROV. 

We had no idea what we were getting ourselves into. 

The very first OpenCTD prototype.

Seven years and five iterations later, we are releasing the long anticipated OpenCTD rev 2 as well as the comprehensive Construction and Operation Manual! OpenCTD rev 2 builds on over half a decade of iteration and testing, consultation with oceanographers, engineers, developers, and makers around the world, extensive coastal and sea trials, and a series of workshops designed to test and validate the assembly process. 

The OpenCTD can be built in two days by someone with no electronics experience using parts available from hardware stores and major online retailers and electronics suppliers as well as a few 3D-printed components for about $300. It is rated to depths of 140 meters, providing access to the majority of the world’s continental shelf for a fraction the cost of a traditional research cruise. It can be deployed by hand from any vessel. Data is stored as tab delimited text files that can be accessed by almost all major analytical software, from R to Excel. 

And rev 2 has an external magnetic switch! Which means you no longer have to open the housing to turn the device on and off.

Everything can be found in the OpenCTD GitHub Repository. A citable pre-print of the OpenCTD Construction and Operation Manual has been uploaded to MarXiv if you use it in your research. 

Our goal has always been to provide a platform for other ocean stakeholders to build upon and expand. While the last revisions of the OpenCTD software pushed the limits of the tiny Arduino computer, the new build has a massive amount of headroom for adding custom software to support new sensors, enhanced onboard analytics, incorporate new features, and expanding its capabilities in novel and exciting ways. We release the software open-source with no restrictions on use, modification, or commercialization. 

And of course, we’re not even close to being finished. The OpenCTD rev 2 represents the most minimal stable iteration of what the platform can become. It’s a foundation with unlimited potential for expansion. We focused on simplicity, reliability, and accessibility to provide a core device that you can trust, that teaches the basics of DIY instrumentation development, and that allows for unrestricted adaptation to suit your needs. 

This year we’re working on establishing 501(c)3 non-profit status for Oceanography for Everyone so that we can continue growing and supporting the community working on OpenCTD as well as our other tools. We’re working on a module that will increase the OpenCTD’s depth rating to 300 meters. We want to add Bluetooth for data access, charging options for long-term deployments, faster, more accurate temperature probes, and, as always, more sensors. Russell may finally get his bucket speaker communication module.

I’ve also made it my personal mission to build and deliver 100 OpenCTDs to individuals, groups, and organizations around the world. If you want to support that effort, subscribe to my Patreon campaign (which also helps keep this site running). There’s even a reward tier if you want me to build you an OpenCTD. 

We started this project with a very simple mission: The Ocean belongs to Everyone and everyone should be able to access the tools to study it. With the OpenCTD rev 2, for the first time I finally feel like we’re liking up to that ideal.

There are hundreds of people to thank, but a huge thanks goes out to David Lang and Eric Stackpole at Sofar Ocean, Jake Levenson, Kim Martini, Amy Freitag, Ian Black, our co-developer Russell Neches, and all the students who have participated in the last year of construction workshops, including David Shiffman (who graciously volunteered to test our claim that “someone with no electronics experience whatsoever could build one of these in 2 days”).

Share this:

  • Click to share on Bluesky (Opens in new window) Bluesky
  • Click to share on Facebook (Opens in new window) Facebook
  • Click to share on Reddit (Opens in new window) Reddit
  • Click to share on Threads (Opens in new window) Threads
  • Click to share on WhatsApp (Opens in new window) WhatsApp
  • Click to share on Mastodon (Opens in new window) Mastodon

Related

Tags: oceanography for everyone OpenCTD

Post navigation

❮ Previous Post: Shark Week 2019 reviews and thoughts
Next Post: We want to give you an ROV! ❯

You may also like

Conservation
Open-source science hardware for an Open Ocean: Reflecting on the Year of the OpenCTD
January 8, 2025
Oceanography for Everyone
Community Oceanography with low-cost, open-source CTDs
September 23, 2022
The Open CTD Project
What can we do with an OpenCTD – high resolution hurricane monitoring
June 3, 2013
Featured
A calling card for oceanographers
May 24, 2024

One thought on “The next generation of low-cost, open-source oceanographic instruments is here! Meet the OpenCTD rev 2!”

  1. Jim N. says:
    January 23, 2020 at 2:50 pm

    This is fantastic, Andrew! Thanks again for keeping up with this.

Comments are closed.

Recent Popular Posts

Shark of Darkness: Wrath of Submarine is a fake documentaryShark of Darkness: Wrath of Submarine is a fake documentaryAugust 10, 2014Michelle Jewell
My "Follow ocean science and conservation experts on Bluesky and Instagram" assignmentMy "Follow ocean science and conservation experts on Bluesky and Instagram" assignmentNovember 19, 2024David Shiffman
Sustainable Seafood, Endangered Species, and Jaws: Some upcoming talks and panelsSustainable Seafood, Endangered Species, and Jaws: Some upcoming talks and panelsMay 8, 2025David Shiffman
What can the funniest shark memes on the internetz teach us about ocean science and conservation?What can the funniest shark memes on the internetz teach us about ocean science and conservation?November 8, 2013David Shiffman
Our favorite sea monsters – Ningen (#4)Our favorite sea monsters – Ningen (#4)September 7, 2010Andrew Thaler
The story of the pride flag made from NASA imagery: Bluesky's most-liked imageThe story of the pride flag made from NASA imagery: Bluesky's most-liked imageSeptember 27, 2024David Shiffman
I turned my woodshop into a personal solar farm.I turned my woodshop into a personal solar farm.June 21, 2021Andrew Thaler
Deep-sea mining, marine protected areas, and the eternal struggle to open doors: This Week in Andrew (and Angelo) Doing PodcastsDeep-sea mining, marine protected areas, and the eternal struggle to open doors: This Week in Andrew (and Angelo) Doing PodcastsMay 7, 2025Andrew Thaler
Here's what I teach my students about finding jobs in marine biology and conservationHere's what I teach my students about finding jobs in marine biology and conservationApril 10, 2024David Shiffman
Alberta, Canada is the proud owner of the largest man-made pyramid on the planetAlberta, Canada is the proud owner of the largest man-made pyramid on the planetOctober 16, 2012Andrew Thaler
Subscribe to our RSS Feed for updates whenever new articles are published.

We recommend Feedly for RSS management. It's like Google Reader, except it still exists.

Southern Fried Science

  • Home
  • About SFS
  • Authors
  • Support SFS


If you enjoy Southern Fried Science, consider contributing to our Patreon campaign.

Copyright © 2025 Southern Fried Science.

Theme: Oceanly Premium by ScriptsTown