1)
What goes up and down?
1.
Radak, Malbim: People on the boat.
2)
Do they truly go up to Shamayim?
1.
Radak: No - the wave lifts the boat in the air. After it passes, the boat descends.
3)
What is the meaning of "b'Ra'ah Sismogag"?
1.
Radak: Their heart melts amidst the evil and fear lest they drown in the sea.