The watch itself is certainly nothing anyone would kill me for <g>.

But yes, the entire microSD card is encrypted using BitLocker in case it happens to be lost or otherwise falls into the wrong hands. My will contains the decrypt password.

If you think about it, my data is as safe as I am --- if not safer. The authorities aren't going to spend any effort to recover a memory card --- but they will to recover a body with a memory card attached..

Since this is always with me, it serves as the off-site copy in my 3-2-1 backup plan.

https://www.backblaze.com/blog/the-3-2-1-backup-strategy/

If the threat model includes murder, they can get my encrypted data anyway.

See XKCD #538: https://xkcd.com/538/