https://lone.design/product/drop-ship-rust-plugin/
The Dropship plugin allows cargo containers to fall off of the cargo ship as it traverses the ocean. These containers will slowly float towards the shore. They also can spawn randomly in the ocean and float towards the shore.
You will see a locked crate marker where the cargo container is. In some cases, as you approach the container, it may sink in the water. In this case, you’ll need diving gear to get to it. Once you are at the container, press E at the end of the container and it will open, revealing up to 3 supply drops inside! If the container does not sink when you arrive, it may start sinking after you open it up. Inside of the container, you will find up to 3 supply crates. The small black box at the bottom of the container is not lootable.