If he were to tell his crew about the dangers that awaited them they never would have sailed.
He didnt want to scare them so they wouldn't leave.
The Underworld and then through the Harpies and sea monsters; Scylla and Charybdis.
Odysseus did not warn hiscrew about Scylla because he was afraid they would all hide under the decks and not fight the monster. He needed them to be brave, so they could escape the narrow passage between Scylla and Charybdis
Odysseus chooses not to tell his men about the monsters, such as Scylla and Charybdis, to prevent panic and maintain their morale. He understands that revealing the full danger could lead to fear and indecision, which might compromise their safety and resolve. By keeping the information to himself, he aims to maintain control over the situation and ensure they face the challenges ahead with courage. Ultimately, his leadership is focused on guiding them through perilous waters without succumbing to despair.
Calypso allows Odysseus to leave her island after Athene asks Zeus to tell Calyspo that if she doesnt allow Odysseus to leave her island that if she doesnt that Zeus will strike her with a thunderbolt and kill her as he is not a prisoner to her island and need to get home to be with Penelope (his wife). Zeus sends Hermes the messenger God to tell Calypso. Although Calypso is furious and doesnt want Odysseus to leave, she lets him because obviously she doesnt want to die so she helps him build a raft and gives him gifts for his journey home.
If you analyze Odysseus you will find that he is prideful and cocky. In this case, we see Odysseus push aside his intelligence with his pride. He doesnt want to tell his crew that he needed help.
To make sure that his crew stay calm and not think that he's crazy to go up against a giant snake and whirlpool
Odysseus chooses not to disclose the full danger of facing Charybdis and Scylla to his men because he wants to prevent them from succumbing to fear and despair. By only informing them about the Sirens, he maintains their morale and focus on the immediate challenge, allowing them to concentrate on navigating past the enchanting songs of the Sirens. Revealing the additional dangers would likely overwhelm them, jeopardizing their ability to face the trials ahead. Ultimately, Odysseus seeks to protect his crew's resolve and ensure their survival during the perilous journey.
about the sirens, scylla, charybdis, the sun god, and not to eat the Helios cattle. to never sleep with a chik you don't know
By keeping the knowledge to himself he likely saved most his men, save the six that were lost to Scylla, as a ship divided as his men would have been would not have made it at all.
Odysseus chooses not to inform his crew about Scylla and Charybdis because he wants to prevent panic and maintain their morale. He understands that revealing the dangers could demoralize them and lead to chaos, potentially jeopardizing their survival. Instead, he opts to keep the information to himself, believing that his leadership and experience will guide them through the perilous strait without alarming his men. This decision reflects his desire to protect them and maintain control in a dire situation.
So they did not become scared and decide to turn back. By the time they reached Scylla, all of the men were focused on Charybdis (the whirlpool), and did not have time to worry about being eaten by Scylla until it was too late.