At some point a couple centuries back, somebody in North America got the idea to take the perfectly serviceable regular past tense form of dive — namely dived — and turn it into the irregular form dove (like drove).  You can plot its course to ultimate victory in this graph derived from Google Books:

But they didn’t finish the job, because the past participle is still dived: someone who would say She dove into the water would still say She hasn’t dived into the water. So something of a Frankenstein’s monster, grafted together from different parts. I recently stumbled across another such monstrosity. The verb pet — for me at least — has an irregular past tense like let or set, where nothing changes: Yesterday she pet the cat and let it out. But its past participle is a ‘regular’ one with –ed: She hasn’t petted the cat or let it out. So both of them are kind of hybrids, with past tense forms transformed into irregular verbs but past participle forms left to be like regular verbs:

regular verb	hybrid verb	irregular verb
she thrives she frets	she dives she pets	she drives she lets
she thrived she fretted	she dove she pet	she drove she let
she has thrived she has fretted	she has dived she has petted	she has driven she has let

Which is bizarre: why take perfectly good regular verbs and change them into one-off oddities?