Underwater rugby (UWR)...
Is an underwater team sport. During a match two teams try to
score a negatively buoyant ball (filled with saltwater) into the
opponents’ goal at the bottom of a swimming pool. It originated
from within the physical fitness training regime existing in
German diving clubs during the early 1960s and has little in
common with rugby football except for the name. It was
recognised by the Confédération Mondiale des Activités
Subaquatiques (CMAS) in 1978 and was first played as a world
championship in 1980.