| Basque Auxiliary Navy Marina de Guerra Auxiliar de Euzkadi Eusko Itsas Gudarostea | |
|---|---|
.jpg) Churruca-class destroyer Císcar of the Basque Auxiliary Navy | |
| Active | 1936–1937 |
| Country | Spain |
| Branch | Spanish Republican Navy |
| Type | Navy |
| Role | Coastal defence and minesweeping |
| Engagements | Spanish Civil War |
| Commanders | |
| Commander | Joaquín de Eguía y Unzueta |
| Insignia | |
| Naval ensign | .svg) |
| Naval jack | .svg) |
.jpg)
The Basque Auxiliary Navy (Spanish: Marina de Guerra Auxiliar de Euzkadi, Basque: Eusko Itsas Gudarostea) was a section of the Spanish Republican Navy operating in the Bay of Biscay between 1936 and 1937. The naval force began their operations in October 1936 at the behest of the autonomous Basque Government. The main Basque Navy base was at Portugalete.