'Tattoogate' breaks as dark ink leaves Apple Watch heart rate sensor flummoxed

Have you got a wrist tattoo at all? Then if you were thinking of buying an Apple Watch, you may have a problem with the freshly launched device.

Yes, “Tattoogate” has now been born following reports (spotted by Mashable) that some users with dark-inked wrist tattoos may have an issue with the tattoo interfering with the Apple Watch’s ability to sense contact with the user’s wrist.

Several users have posted YouTube videos of the smartwatch, including Nathan Hodgetts with a clip showing that the timepiece won’t accept his PIN code because it can’t sense contact with his skin (it also shows his PIN needs to be changed from ‘1111’, incidentally).

And another Apple Watch owner, Michael Lovell, posted a video (see above) showing the workout app in action monitoring a simple outdoor walk, first on his left wrist which has no tattoo – and it works fine – and then on his tattooed right wrist, where the app keeps pausing itself, messing up the readings.

He contacted support over the issue, and notes that Apple’s response was: “They said it must be something to do with the sensors losing contact with the skin and will replace it.”

The fact that it works fine on the non-tattooed wrist, though, surely shows this is an issue with tattoos and not some fault with the watch itself?

A lengthy Reddit thread has sprung up concerning the problem, with some users noting they are having similar issues to the original poster. Steve Isaacs said: “I have black ink tattoos just under the watch's sensors and have very spotty results with notifications sometimes … I find that when I do an Outdoor Cycle workout, the watch pauses itself over and over.”

However, it seems there may be some sort of workaround available – namely turning off wrist detection, as Isaacs observes: “Once I turned off wrist detection it seemed to fix it.” The original poster said that after turning off wrist detection, messages then started being pushed to his Apple Watch (when they weren’t before).

Mashable (and some Reddit commenters) observes that this could have something to do with the way the smartwatch’s heart rate sensor works, and its use of photoplethysmography (easy for us to say). In other words, as Apple puts it the watch uses “green LED lights paired with light sensitive photodiodes to detect the amount of blood flowing through your wrist”, and the dark tattoos could be interfering with this detection process.

Certainly this issue requires further looking into, but it sounds rather ominous for those who have tattooed wrists.