One informal meaning of “whale” is “to beat.” Huck Finn says of Pap that “He used to always whale me when he was sober.”
Although the vocalist in a band may wail a song, the drummer whales on the drums; and lead guitarists when they thrash their instruments wildly whale on them.
Although this usage dates back to the 18th century and used to be common in Britain and America, it is now confined mostly to the US, and even there people often mistakenly use “wail” for this meaning.
This week on the podcast we have a visit from Geoffrey Pullum and discuss eggcorns.
Bonus "eggcorn" cartoons: