This is a very recent thread on watches - the watch threads pop up every year. A Search on "watches" works.
watches during Plebe summer?
https://r.tapatalk.com/shareLink?ur...&share_tid=26239&share_fid=79838&share_type=t
IMPO, it's probably not worth it to wear to I-Day. After PS, you can figure out the uniform and grooming regulations about what watches are allowed in uniform and what will work best for you as a mid. Remember you will only have your iPhone periodically during PS.
Casio G-Shocks seem to be a current favorite across all SAs.
I am sure current mids or recent grads will offer good input.
Your PTR will have specifics, probably in the section about cell phones, jewelry, electric shavers and cosmetics. If it's the same as last year, you can bring a watch. It will be stored for you until after PS. You can't wear it.
Edit: Currently there are prohibitions against having smartphones or other devices with wifi and other capabilities in certain secure spaces for information security reasons - but that's way down the career path for you. Tech will no doubt have pushed more boundaries by then!