I don't think it's simply the current price of the fuel that influences whether or not to proceed with a trip. While it may be a few hundred extra dollars for the trip..it's also the increase in the price of groceries..and the increase in what it costs us daily/weekly to commute to work. These increases are creeping into the alloted funds for vacation. So would a few hundred dollar increase to the fuel budget be enough to break the bank and cancell a trip....probably not. Only it doesn't stop there..,I believe it's more a cumulative effect the price of gas has on our daily lives that is causing some people to reconsider where they should spend the hard earned dollars. People are very hesistant to spend on what would be a luxury like a vacation, when you may need that money to put food on the table, or gas in the tank to get to work. I believe we are only now starting to see the effect the gas prices will have on tourism.
Just wanted to add that we live on Long Island..and I've noticed more boats in driveways with "For Sale" signs on them, than I have in many years.

The fuel for boats is even more than that for the cars.