c/5 diagonal is a diagonal speed that is equivalent to one fifth of the speed of light.
The first c/5 diagonal spaceship to be discovered was 295P5H1V1 and was found by Jason Summers on November 22, 2000. No other spaceships of this speed were discovered until January 8, 2005, when Jason summers found the much smaller 86P5H1V1. In July 2006 Nicolay Beluchenko discovered three new c/5 diagonal spaceships, including the asymmetric 67P5H1V1. The smallest known c/5 diagonal spaceship, 58P5H1V1, was discovered by Matthias Merzenich on September 5, 2010.
- c/5 orthogonal
- List of important speeds
- List of spaceships with speed c/5
- List of puffers with speed c/5