The rock in front of the cave

Athena's rock

As it had to have been quite a small boat, Odysseus probably needed to row up and down to the cave twice and then paddle across Rouda Bay to the beach at Mikros Gialos, which adds up to about 8 kilometres in total. With an average speed of 8 kph it would've taken him an hour. We'll add another half hour to load and unload the treasure, so all in all it would've taken about an hour and a half to hide the treasure and get to the beach.