sea - that is, a lake, or pool formed from the outspreading of a river. Job lived near the Euphrates: and “sea” is applied to it (Jer 51:36; Isa 27:1). So of the Nile (Isa 19:5).
fail - utterly disappeared by drying up. The rugged channel of the once flowing water answers to the outstretched corpse (“lieth down,” Job 14:12) of the once living man.