Apocrypha pointed me to
http://en.wikipedia.org/wiki/HNS_Velos#Hellenic_Navy this morning, which was a cute little read.
But I was more interested in the modern Greek translation of the name. Apparently, Velos is the English-phonetic of βέλος, which means 'arrow'. I find that I like this much better than the French translation of vélos, which is 'bicycle' and which has been a mildly sore point for a good ten years.