Your Apple Watch can wake to the watch face, or your last activity, when you raise your wrist. Called Wrist Raise, this handy feature uses the heart rate sensor, which requires skin contact.
But according to users on social media channels like Twitter and Reddit, tattooed wrists fool the Apple Watch into thinking it's not on a wrist in the first place, causing all sorts of issues.
For starters, the Activate on Raise Wrist function may stop working or may perform erratically. More problematic than that, people with tattooed wrists may stop receiving notifications. In addition, inaccurate heart rate readings have been reported, too, as dark tattoos can throw off Apple Watch's heart rate sensor and cause the Workout app to pause every now and then.
And because the sensor interferes with dark-inked tattoos, the device will request your passcode after mistakenly thinking it's lost skin contact. Another side-effect: Apple Pay, another feature that requires skin contact, gets disabled, causing you to re-enter the security PIN.