what light does the opening scene throw on the danger that the sea could pose to ship.from act 1 scene 1

There are storms, sandbars, rocks that could sink ships,

"My wind cooling my broth

Would blow me to an ague when I thought

What harm a wind too great at sea might do.

I should not see the sandy hourglass run,

But I should think of shallows and of flats..."

the dangerous caused on the ship as shown in the opening scene as first told by salarino & salanio