What the sailors taught me

I went into my VisNav research with a simple picture: blind sailors struggle to hold a course, so give them a wristband that buzzes left or right. The people I interviewed liked that idea. Almost everything else they told me surprised me.

The biggest surprise came before I had built anything. During Blind Sailing Week I tested the idea with no electronics at all. I sailed with a helm who is severely sight impaired and profoundly deaf, so spoken instructions were never an option. We agreed three signals: a hand on the left shoulder meant steer left, a hand on the right shoulder meant steer right, and a hand in the middle of the back meant on course.

They picked it up straight away. Steering by touch alone, they held a straighter course than I manage when I steer by eye. That was the moment I stopped seeing touch as a workaround. For this one job, it works better than sight.

What else changed the design

• Hearing is already overloaded. One experienced sailor described relying on audio as "a bit of an audio overload". Touch gives steering its own channel and leaves hearing free for wind, crew and hazards.
• Plus and minus buttons are not enough. An experienced helm wanted jumps of 5, 10 and 90 degrees. Others wanted to set a heading by voice, while a younger sailor warned that accents can confuse voice control. The app needs both.
• Tillers flip everything. Push a tiller left and the boat turns right. The wristbands have to talk about where the boat should go, and the app has to make that obvious.
• Every phone is set up differently. One sailor uses magnification, another a screen reader, and one wanted the spoken announcements switched off completely.
• Sighted sailors want it too. Two people said it would help anyone on a long night passage who is tired of staring at a compass.

My favourite answer came from someone who had sailed twice. Asked if they had ever got disoriented, they said they had "started sailing in the sea towards France". That is exactly the moment VisNav is for.

I designed the first version for visually impaired sailors. The interviews mean I can design the next one with them.