Exegesis:

pleontōn de autōn ‘as they sailed (along).’ autōn refers to Jesus and his disciples. pleō.

aphupnōsen ‘he fell asleep.’ Subject is Jesus.

kai katebē lailaps anemou eis tēn limnēn ‘and a squall of wind came down upon the lake,’ as if descending from the surrounding mountains.

lailaps ‘whirlwind,’ ‘hurricane,’ here with anemou ‘a squall of wind.’

kai suneplērounto kai ekinduneuon lit. ‘and they were filling and were in danger.’ The subject of both verbs is Jesus and his disciples (as in pleontōn autōn), not the disciples only as in the first clause of v. 24. In suneplērounto (also 9.51 but in a different meaning) what happens to the ship is said to happen to the crew. The imperfect tense of both verbs serves to bring out the situation in which they find themselves due to the squall of wind.

kinduneuō ‘to be in danger.’

Translation:

They sailed, or, ‘they boat-ed’ (e.g. in Toraja-Sa’dan, Batak Toba, just as in Greek), ‘they were driving’ (Marathi, same verb as used of carts, motor-cars, etc.); or still more generically, ‘they were going so’ (Sranan Tongo).

He fell asleep. Other idiomatic expressions are, “he dropped off to sleep” (Phillips), ‘his sleep stole Jesus’ (Toraja-Sa’dan), ‘his-eyes became-sleepy’ (Batak Toba).

A storm of wind, or, ‘a heavy storm,’ ‘a roaring wind,’ ‘a gale,’ a term referring to heavy wind with rain, etymologically related with the word for ‘west’ (Toraja-Sa’dan), ‘a very strong wind,’ lit. ‘a mother of winds’ (Tboli, which has also another and more forceful idiom: ‘a horse of winds’).

Came down, or, ‘began to blow/rage,’ ‘came’ (Sundanese), ‘came suddenly (lit. broke came)’ (Sranan Tongo), “struck” (New English Bible), ‘released itself’ (Marathi), as idiom may require; Tboli shifts to, ‘they ran into a very strong wind.’

They were filling with water, or, ‘water began to fill the boat’ (Marathi). Some idiomatic renderings are, ‘they made with water’ (Willibrord), ‘the(ir) boat was-entered-by water’ (Bahasa Indonesia), ‘the boat took water’ (Sranan Tongo). Ekari uses a specific word for water in a boat needing to be bailed.

And were in danger, or, ‘and were in distress’ (Nieuwe Vertaling), ‘so that they nearly perished’ (some Indonesian languages), ‘they were nearly sinking’ (Toraja-Sa’dan, similarly Sranan Tongo, lit. ‘they sought to sink’).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.