I had a friend who purchased a brief family name history in 1992. Along with the brief summation of the origin of the name Swim it also included a description of the Swim family crest. I am posting it's description for all the Swims out there.
Blazon of arms:Azure, a bend argent charged with 2 fleur-de-lis of the first in bend.
Crest: A fleur-de-lis per pale argent and azure
Azure(blue) symbolizes truth and loyalty.
This crest's origin is Germany.