So, my wife and I found that if we went ro Mermaids Hideaway we could fish for pondies easily catch five each with barely a struggle. However, with the new storage crates, we have found that we can shed even more time off (without having to run back and forth from the ship).
Fast Pondie Fishing Video
I can't stress enough that this way of getting gold fast isn't for everyone and that the more crewmmates you have, the faster you will get the gold.