Wiktionary
bellies up
vb. (en-third-person singularbelly up)
Usage examples of "bellies up".
Massa Stubb say dat you can fill your dam bellies up to de hatchings, but by Gor!
Day Two they gave us halberds and pikes from the Tower and turned the Tin Bellies up in their fancy kit.
Two or three were almost instantly stricken with paralysis and floated to the surface, bellies up.