You can't, actually, see the wall. It's satellites, drones, and automated sentry guns, only visible as crowdsourced online heatmaps, every data point somebody's death.
Some people stare at the shifting tides for hours, seeking routes of relative safety, trying to learn to think like a wall. The best make a living taking others across, whether cartels or refugees from the undeclared civil war.
They say it's the money, but none has ever retired. When they feel they can no longer keep up they leave their phones behind and walk alone and blind across the sand.