Swan is a c/4 diagonal spaceship producing some useful sparks. It was found by Tim Coe in February 1996. On February 20, 1996 Noam Elkies noticed that it could be made into a small boatstretcher. It can also be combined nontrivially with a Canada goose. In November 2000 Jason Summers found a period 8 glidereflective tagalong for two swans. This was the first c/4 diagonal spaceship with a period other than period 4 to be found.
Gallery
x = 28, y = 28, rule = B3/S23
5b2obo7b3o$5bo3bo6bo$5bo4bo7bo7b2o$7b2o7bobo4b2obo$9bobo4b3obo2b2o$3o
12bo3b2o2b2o$o10b2ob4ob2o$3bo8b7o$o2bo$bo2bo$2bo$4bobo$6b2o$7bo6b3o$6b
2o6bo2bo$5b3o5bo3bo$2ob2ob2o7bo$o3bob2o9b2o$ob3o2bo5bo6bo$5b2o8b3o3bo$
4b3o14bo$19bo$20bo$3b3o$3b3o2$2b2o$2bo!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ AUTOSTART GPS 2 ZOOM 9 TRACKLOOP 8 1/4 1/4 ]]
 Two swans pulling a period 8 tagalong (click above to open LifeViewer) RLE: here Plaintext: here 

x = 24, y = 15, rule = b3/s23
12b2o10b$3o9bobo9b$o2b3o6bo9bob$bobo16b2obo$6bo4b2o2bo3b2o2bo$4bo6b2o
2bob2o2bo2b$6bob2obo3b5o4b$15b2o7b$7bo2b6o8b$8b7o9b$10b3o11b2$13bo10b$
12bobo9b$13b2o!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
 A swan stretching a boat (click above to open LifeViewer) RLE: here Plaintext: here 

See also
External links
 49P4H1V1.1 at Heinrich Koenig's Game of Life Object Catalogs