---
title: "Global RGB bathymetry tileset | Guides | Map tiling hosting | Data hosting"
description: "Understand bathymetry and global underwater relief models."
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Global RGB bathymetry tileset

Bathymetry is describing the underwater depth of ocean floors. Together with the topographical data,  a global relief model can be created.

The encoding process is the same as in the [RGB Terrain by MapTiler](https://docs.maptiler.com/guides/map-tiling-hosting/data-hosting/rgb-terrain-by-maptiler): the elevation is split into tiles and each tile has elevations encoded in a WebP image where each pixel color (red, green, blue) can be turned into elevation using a smart formula:

`elevation = -10000 + ((R * 256 * 256 + G * 256 + B) * 0.1)`

The format allows storing elevations very efficiently (3 bytes vs. 4 or 8 bytes in the case of floating-point numbers) with sufficient precision.

![mceclip1.png](./11036986748817_a08301b758.webp)

We are already using the dataset as a hillshade layer in the **_Ocean map:_**

**_![mceclip2.png](./11037201968529_3aa0fcc4aa.webp)_**