Imagine you have a big toy boat that you like to play with in your bathtub. But this boat is too big to fit in your bathtub all at once, so you need to bring it in and out of the tub in pieces. You also need to make sure the water in the tub is deep enough for the boat to float.
The Santa Fe Dock and Channel Company works kind of like that. They help big ships bring their cargo in and out of a harbor safely. Just like your toy boat, these big ships are too big to fit in shallow water, so the company helps dig a deep channel that the ships can travel through.
Once the channel is dug, the company maintains it by keeping water deep enough for the big ships to travel through. They also make sure the docks where the ships load and unload their cargo are safe and in good condition.
Basically, the Santa Fe Dock and Channel Company helps big ships get in and out of a harbor safely and efficiently, just like how you make sure your toy boat is safe and floating in your bathtub.