# Centreboard

> What is a centreboard?

- Category: Boat design › Sailboat appendages
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/centreboard/ · JSON: https://xemstudio.com/api/geometry?object=centreboard · Plain text: https://xemstudio.com/objects/centreboard/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- A centreboard pivots out of a slot in the hull; lowering it adds lateral lift, raising it reduces drag and allows shallow water and trailering (Wikipedia).
- It is more complex than a fixed keel and its case adds drag and takes interior space (Wikipedia).
- The file is a reference example built by Xem Studio from the numbers above (Illustrative.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

## Sizes

| parameter | value or range | source |
|---|---|---|
| Motion | pivots | Wikipedia (Centreboard) |

## Where the files are

- Wikipedia: [Centreboard](https://en.wikipedia.org/wiki/Centreboard) — web — Publisher's page; dimensions are facts
- Wikipedia: [Daggerboard](https://en.wikipedia.org/wiki/Daggerboard) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/centreboard/index.json · license: https://xemstudio.com/files/hardware/centreboard/LICENSE.md

- centreboard-appendage: [STEP](https://xemstudio.com/files/hardware/centreboard/centreboard-appendage.step) · [STL](https://xemstudio.com/files/hardware/centreboard/centreboard-appendage.stl) — centreboard: 300 mm deep, 60 mm chord, NACA 00-series foil

## Questions

**Why pivot?**

So it can kick up on grounding and be partly raised (Wikipedia).

## Fits with

- [Fin keel with ballast bulb](https://xemstudio.com/objects/fin-keel-bulb/)
- [Spade rudder](https://xemstudio.com/objects/spade-rudder/)
- [Skeg-hung rudder](https://xemstudio.com/objects/skeg-hung-rudder/)
- [Daggerboard](https://xemstudio.com/objects/daggerboard/)
- [Canting keel](https://xemstudio.com/objects/canting-keel/)
- [Rigid wing sail](https://xemstudio.com/objects/wing-sail/)