How does Odysseus survive the dangers posed by the Sirens, Scylla, and Charybdis in Homer's Odyssey?
In the twelfth book of Homer's Odyssey, we hear about Odysseus' encounter with the Sirens, as well as his encounter with Scylla and Charybdis.
Odysseus manages to make it past the Sirens because of advice given to him earlier in Book 12 by the goddess Circe. She is the one who tells him about putting wax in the ears of his crew and about having them tie him to the mast of his ship:
Plug your comrades’ ears with softened beeswax lest they listen, and row swiftly past. And if you must hear, then let them first tie you hand and foot and stand you upright in the mast housing... (A.S. Kline translation)
Circe also provides Odysseus with information about how to avoid the dual threats of Scylla and Charybdis. The Charybdis is basically a whirlpool and Scylla is a really nasty multi-headed and multi-handed sea monster. Because it is impossible to avoid both of these dangers, Circe advises Odysseus to steer closer to Scylla than to Charybdis, "since it its better to mourn six men than your whole crew."
We should also note that near the end of Book 12, after Odysseus is shipwrecked, he is swept back to the location of Scylla and Charybdis. Luckily, he was able to hang on to a tree branch, avoid the notice of the Scylla, and then manage to find some timber from his ship to hold on to when the Charybdis spewed out some of the wreckage.