Have you wondered as I have why the Pacific Ocean is higher ....?

than the Atlantic so ships need to be 'raised' through 'locks' at the Panama Canal?

Ships have to be raised by locks at both ends of the Panama Canal, not just the Atlantic end. I have heard that the Pacific sea level at the Canal is 4' higher than sea Atlantic sea level.

From PSMSL:
"Sea level is about 20 cm higher on the Pacific side than the Atlantic due to the water being less dense on average on the Pacific side and due to the prevailing weather and ocean conditions. Such sea level differences are common across many short sections of land dividing ocean basins."