You, being a Californian, know that distance is irrelevant when it comes to issues about our southern border. If someone gets removed from the ship, for whatever reason, the regulations still apply, 90 miles or 90 feet. Maybe you mean that it would be possible to drive rather than fly back to the US, but crossing the border will still require documentation, passport or otherwise. The risk is small, maybe, but the risk still does exist. I would not want to be the one to find out what that might be.