HMS Dagger is a Cutlass-class fast patrol boat of the British Royal Navy.

She is a fast patrol boat with a maximum speed around 41 knots (76 km/h; 47 mph) designed for sovereignty protection and coastal security duties.

[5] In April 2023, Dagger was called upon to escort the Spanish patrol ship Infanta Cristina as she made an illegal transit.

In the Spanish view, the 1713 Treaty of Utrecht, which Spain signed, incorporated British sovereignty over the land, but not the waters, of Gibraltar.

[7] In August 2024, HMS Dagger was called upon to escort the Spanish Navy patrol vessel Rayo which, in the British view, made an illegal transit through Gibraltar territorial waters.