Why couldn’t they just dig a trench big enough to connect the Pacific and Atlantic instead of the lock system of the Panama Canal?

Question

Saw a post about the canal, and this question popped up.

In: 9

Answer 1

The two oceans aren’t at the same level. Tides and currents make it rarely even.
Without locks the strength of the tidal differences would be massive. Although it would be quite a sight, there is no way ships could navigate the tidal currents safely.