¿Can you believe in an old earth and a global flood?

In Biblical times the world was "flat". So if there was a regional flood, then the whole world (as they saw it) must have been flooded.
You may have noticed that the mountains rose from the sea. This apparent observation would have occurred as one approached an island on the sea when the earth was flat. Similar verbage has been used by sailors in distress when recording their evperiences as they discovered land.
One must understand the context before understanding the words. Edited by Libmr2bs, : No reason given.