The book of Jonah plays with the concept of directionality. God’s command to arise, “ἀνάστηθι,” is paired with Jonah’s initial complicity in 1:3a, “ἀνέστη,” “and he arose.” This is contrasted with Jonah’s downward movement. He goes down, “κατέβη,” into Joppa (1:3b), and then he makes a lateral move as he embarks, “ἐνέβη,”on a ship going to Tarshish (1:3e).
The translator’s sensitivity to the narrative’s geographical setting leads him to translate וַיֵּרֶד, “he went down,” with ἐνέβη, “he embarked.” The rendering τοῦ πλεῦσαι, “in order to sail,” for לָבוֹא, “in order to go,” reinforces this. Though the change weakens the original Hebrew connection between קוּם, “arise,” and the repetition of וַיֵּרֶד, “he went down,” it does not destroy it since both words, κατέβη and ἐνέβη, are built upon the same root, βαίνω. Though the connection between the two words is tenuous, the observant reader is able to make the connection.
This is not true in 1:5f, where the Hebrew וַיֵּרָדַם, “and he slept soundly,” is translated with ἔρρεγχε, “he snored.” The play on words between יָרַד, “he went down,” and רָדַם, “he slept soundly,” is not communicated in the Greek text. John Beck writes,
“The root קוּם is consistently represented by a form of ἀνιστήμι. But the descent of Jonah that is evident in the Hebrew narrative from the time he heads for the seaport is translated by three different roots: καταβαίνω, ἐνβαίνω, ἐρρέγχω. Again an important tool in the characterization of the Hebrew Jonah is lost”.
Characterization is indeed lost. The original author of Jonah uses this Leitwort not only to communicate Jonah’s geographical distance from God, but also to emphasize Jonah’s deliberate disobedience with each move he makes. Jonah will go to whatever depths necessary to get away from God and not escape his commission to deliver God’s message to Nineveh.
Whether or not it was a conscious decision, the translator has developed the geographic setting of the narrative at the expense of a robust characterization of Jonah. This fact becomes more important as the narrative unwinds. Jonah’s request to be thrown overboard is not a selfless act of sacrifice (his life for the sailors). Instead, it is another attempt, in a long sequence of events, to get away from Yahweh. He is prepared to die. In fact, he goes down to Sheol, where the Lord preserves him, hears his cry, and delivers him.
 Translators as Storytellers: A Study in Septuagint Translation Technique, Studies in Biblical Literature 25, (New York: Peter Lang, 2000), 119