Download: Galvanic Fatigue Calculator, Google Play
PALMA DE MALLORCA, SPAIN — 3 September 2026 — Galvanic Works has released the Galvanic Fatigue Calculator, a free app for iOS and Android that estimates how impaired a sailing crew becomes on a multi-day passage and reports it in the one unit everyone already understands: a blood-alcohol equivalent.
Seventeen hours awake produces the same measurable loss of performance as a blood-alcohol concentration of 0.05%. After twenty-four hours it is 0.10%. That finding, published in Nature by Drew Dawson and Kathryn Reid in 1997, is well established in road and aviation safety, and it sits behind the hours-of-rest rules that commercial crews work to. Recreational sailors have no equivalent: no regulator, no watch-keeping standard and, until now, no tool, while broken watches make seventeen hours awake an ordinary night rather than an exceptional one.
What the app does
A skipper enters the crew, the passage length, the watch rotation and the sea state. The Galvanic Fatigue Calculator returns an hour-by-hour fatigue curve for every person aboard, showing when each of them peaks, how the circadian low between 02:00 and 06:00 deepens it, how rough water accelerates it, and what a single extra crew member would change. Fourteen watch rotations are built in and any rotation can be built by hand.
“Every sailor recognises this problem and almost none of us can size it,” said Natalie Smith, Founder & CCO of Galvanic Works. “You know the third night is worse than the first. You cannot say by how much, so you plan the watch rotation on habit and hope. This puts a number on it before you leave the dock, which is the only point at which the number is still useful.”
The science, and its limits
The model is built on the two-process sleep science relating time awake and circadian phase to measurable performance loss, drawing on more than fifty published studies. Galvanic Works has also published its own two open-access research papers on sailor fatigue, both currently awaiting peer review, available at galvanicworks.com/research.
The calculator is a planning tool. It is not a medical device, it is not certified, and it does not measure any individual. It estimates what published research says a watch pattern does to a typical person, so that a crew can choose a better one.
“We have made it free and we have made it for everyone, including people who will never buy anything from us,” said Natalie. “Fatigue at sea is not a premium problem. If a short-handed couple crossing the Atlantic changes one watch because of a number on a screen, the app has done its job.”
The same model, running live on the boat
The calculator plans a passage before it starts. Galvanic Voice, the company’s intelligent marine voice alert system, runs the same fatigue model while the passage is happening, and it does so through the Galvanic Pulse bracelets supplied with every unit.
Worn, a bracelet streams its wearer’s movement to the Galvanic Voice unit, which classifies that person as asleep or awake and tracks how much rest they have actually had, rather than how much the watch bill says they should have had. Consumer sleep trackers cannot do this at sea: they assume a wrist only moves when its owner moves it, so every wave reads as an awakening and a sleeping crew member is reported awake all night. Galvanic Works developed a patent-pending method that cancels the boat’s motion and isolates the wearer’s own.
Unworn, the same bracelet becomes the sea-state sensor. A Pulse in a drawer or on the chart table is effectively part of the hull, so it measures how hard the boat is actually moving, which is what a fatigue model needs: not the height of the waves but how difficult they make it to rest.
Availability
The Galvanic Fatigue Calculator has been available on Google Play since 13 August 2026, free, with no subscription and no in-app purchases. The only adverts in it are our own. It is published in English, Spanish, French, German and Italian, in 177 countries and regions.
It has been on the App Store since 27 August 2026, free, on exactly the same terms.
- App Store: https://apps.apple.com/app/id6759550165
- Google Play: https://play.google.com/store/apps/details?id=com.galvanicworks.galvanic%5Ffatigue%5Fcalculator
- The research: galvanicworks.com/research
- Press images: galvanicworks.com/wp-content/uploads/press/fatigue-calculator/
About Galvanic Works
Galvanic Works is a marine IoT company applying science and technology to pleasure sailing boats. Founded, privately held and entirely financed by experienced sailors, the company is based in Mallorca (Balearic Islands), Spain, with the express purpose of improving the safety of pleasure sailors. For more information, visit galvanicworks.com.
Media contact: Natalie Smith, Founder & CCO — natalie.smith@galvanicworks.com
Press images, free for editorial use with a credit to Galvanic Works
