![[Challenge-Solved] glass egg thing](https://lemmy.world/pictrs/image/54d923bf-4a32-46aa-8ece-9ac9bf5e614e.webp){kind=link}
You must log in or register to comment.
Not glass, but hardened resin. Used to track littoral currents and drift. Has metal so it can be found later with a metal detector.
Not glass, but hardened resin. Used to track littoral currents and drift. Has metal so it can be found later with a metal detector.