New Defender's Study Bible Notes
104:25 great and wide sea. The present oceans are deep and wide, whereas the pre-Flood “seas” were relatively narrow and shallow, though numerous. They now contain the drain-waters from the Flood which once were stored in the vast “waters above the firmament” (Genesis 1:7) and the subterranean “deep.”
104:25 innumerable. There are many more marine organisms, both in number and variety, than air-breathing birds, mammals, reptiles and amphibians. This is especially true in the fossil record.
104:26 leviathan. The “leviathan” was a great sea-serpent or dragon (note Isaiah 27:1), almost certainly corresponding to the plesiosaurs or other marine reptiles like dinosaurs now only known as fossils. “Playing” in the deep ocean where ships go, it obviously was not a mere crocodile, as modern commentators allege.