Panama Canal 4

 There are three locks  on each end of the Panama Canal with holding areas to increase and decrease water. The new gates close straight across whereas the old canal gates swung like doors. A tugboat keeps the back of the ship in line. Before entering the canal, a crew enters the ship and takes over control of the ship throughout the canal. They leave the ship after it has passed through the canal. The process took about 8- 9 hours.

We are just pulling into a lock here.

This is the back of the ship as we watch the gate closing.

The gate is almost closed.

Now the gate is closed.

Now I am at the front of the ship waiting for the gate to open.

We are passing through where the gate opened. 

Notice how the gates are hollow.