I bought a new Sealander GMT in January and started to track its timekeeping almost immediately.

When it’s on the wrist I wear it 24/7 and when it’s off the wrist I keep it on a winder.

Every Saturday I reset the time and start a new timing run.

It started around -12 psd and with regular wearing it eventually settled around -5 psd and I’m more than happy with that.

Sadly 2 days ago it went from -5 to +30 and it seems to be getting faster!

Has anyone else experienced this?

I’m am still within the 60 days return window (10 days to go) although I love the watch and don’t want to return it.

I’m going to let it run down completely and then manually wind and wear it for few days to see if makes any difference. Any other advice would be greatly appreciated.

Magnetised?

Guy

Sent from my Galaxy S23 Ultra using Tapatalk

^^^ Sounds possible. Do as you suggested and monitor for a few days. If it’s still out of spec demagnetise it or contact CW and ask for it to be regulated. The 60-day return won’t be in your best interests as you’ve been wearing it 24/7.

I concur with Guy’s guess: excess magnetism typically speeds a watch movement. A spike to +30spd is quite a jump. Check with your local watchmaker to see if they would diagnose it. Demagnetizing can be done at home, or by your local shop pretty inexpensively. Do call CW customer service for advice.

Thanks guys, I never even thought of this. A quick search and I found an App that checks magnetism and…. Yep, you guessed it, the needle went off the scale!
I’ve been racking my brain to figure out what could have caused it, but at least I now know what the problem is.
A demagnetiser has now been ordered.
Thanks again

Ralphhardwick wrote: ↑Sat Mar 08, 2025 9:18 pm Thanks guys, I never even thought of this. A quick search and I found an App that checks magnetism and…. Yep, you guessed it, the needle went off the scale!
I’ve been racking my brain to figure out what could have caused it, but at least I now know what the problem is.
A demagnetiser has now been ordered.
Thanks again

You might be able to actually see if the watch is suffering from magnetism. With the watch is stopped, you might well see a couple of hairspring coils stuck together. This shortens the effective length of the hairspring and causes it to oscillate faster, hence the gaining rate. Usually, this is magnetism, but could just as easily be some sort of contamination on the spring.

Ralphhardwick wrote: ↑Sat Mar 08, 2025 9:18 pm Thanks guys, I never even thought of this. A quick search and I found an App that checks magnetism and…. Yep, you guessed it, the needle went off the scale!
I’ve been racking my brain to figure out what could have caused it, but at least I now know what the problem is.
A demagnetiser has now been ordered.
Thanks again

Your photo appears to be atop a laptop or pc: I won't leave a watch close to or directly upon a laptop.

tikkathree wrote: ↑Tue Mar 11, 2025 5:36 pm Your photo appears to be atop a laptop or pc: I won't leave a watch close to or directly upon a laptop.

It’s actually a Bluetooth keyboard powered by two AAA batteries. That photo was taken several weeks ago and I only held it there for the wrist shot. I still can’t narrow down what caused the issue.

What winder is being used? Cheap ones can magnetize the watch as it is winding.

^^^Also it is cumulative. So every time it will get a little more magnetized.