Almost knightship is a partial spaceship discovered by Eugene Langvagen on March 23, 2004. It would have been an elementary knightship if two cells at the back end were not incorrect after the 6th generation, which provided evidence that small elementary knightships may exist within a considerably small bounding box.
Several more small almost knightships were found by Tomas Rokicki in February 2018, using a SAT solver, of velocities (2,1)c/6 and (2,1)c/7. Further searching by Adam P. Goucher based on these partials led to the finding of a true elementary knightship, Sir Robin.
A further (2,1)c/7 almost knightship was found by Goucher on December 12, 2020.
generation 0 (left) and generation 6 (right) show that the pattern is different by only two cells