Those affected are forced to repeatedly enter their security code as Apple's flagship watch keeps locking.
The issue was first pointed out on Reddit by a tattooed user who complained that his watch would regularly lose connection, and report inaccurate heart rate results.
Scores of other users then reported similar issues.
Apple Watch requests a security PIN immediately after detecting that it has left an owner's wrist, meaning that those affected are forced to repeatedly enter their code.
Darker tattoos appear to cause more problems for the device than light inkings.
The problem should have been foreseeable - Apple has already explained that it measures heart rate by analysing light absorption through the skin.
The Reddit user who first flagged up the problem wrote: "So I thought my shiny new watch had a bad wrist detector sensor.
"The watch would lock up every time the screen went dark and prompted me for my password. I wouldn't receive notifications. I couldn't figure out why especially since the watch was definitely not losing contact with my skin.
"I decided to try holding it against my hand - my left arm is sleeved and where I wear my watch is tattooed as well - and it worked.
"My hand isn't tattooed and the Watch stayed unlocked.
"Once I put it back on the area that is tattooed with black ink the watch would automatically lock again. Just wanted to give anyone a heads up about this issue because I don't see it mentioned anywhere in Apple's support documents."
The wrist detection feature can be turned off, but it stops Apple Pay from working.
Apple has not yet commented.
Link
The issue was first pointed out on Reddit by a tattooed user who complained that his watch would regularly lose connection, and report inaccurate heart rate results.
Scores of other users then reported similar issues.
Apple Watch requests a security PIN immediately after detecting that it has left an owner's wrist, meaning that those affected are forced to repeatedly enter their code.
Darker tattoos appear to cause more problems for the device than light inkings.
The problem should have been foreseeable - Apple has already explained that it measures heart rate by analysing light absorption through the skin.
The Reddit user who first flagged up the problem wrote: "So I thought my shiny new watch had a bad wrist detector sensor.
"The watch would lock up every time the screen went dark and prompted me for my password. I wouldn't receive notifications. I couldn't figure out why especially since the watch was definitely not losing contact with my skin.
"I decided to try holding it against my hand - my left arm is sleeved and where I wear my watch is tattooed as well - and it worked.
"My hand isn't tattooed and the Watch stayed unlocked.
"Once I put it back on the area that is tattooed with black ink the watch would automatically lock again. Just wanted to give anyone a heads up about this issue because I don't see it mentioned anywhere in Apple's support documents."
The wrist detection feature can be turned off, but it stops Apple Pay from working.
Apple has not yet commented.
Link