I arrive in London (Gatwick) the morning of July 25. Plan to take the Chunnel to Paris that morning. I have not pre-purchased a chunnel ticket. Am I going to have a problem purchasing a tickete when I arrive in London? Should I go to the Waterloo station to purchase or is there a place in the Gatwick Airport to make the reservation?
I don't think you will be able to purchase Eurostar tickets at the Gatwick train Station (I'm not 100%certain though). But you definitely won't have any problems securing tickets at Waterloo Station the morning of your departure. They sell them up to 30 minutes before a departure. Eurostar trains run very frequently and rarely sell out. When you purchase tickets at the last minute you will be paying the top fare as opposed getting an advanced far via www.eurostar.com. But since your plane could very easily land late, and there may be long lines at immigration, an advance non-changeable/refundable ticket is not your best option.