How far in advance should I book my airfare?  

According to Hopper.com,

"The Cheapest Time to Book a Flight from the Caribbean is at Least 25 Days in Advance

American fliers looking to transport themselves to the romantic all-inclusives of the Turks and Caicos, the scintillating beaches of Aruba or the rickety rum shacks of Jamaica's Negril, would do well to stop the daydreaming for a moment and practice just a smidgen of forward planning. That's because our stats have shown that flight prices from the United States to the Caribbean region are at their lowest 25 days prior to departure, before shooting up sharply in the weeks immediately before departure."

Priceoftravel.com summed up the data gathered by Kayak.com like this,

 "In early 2015, the fine folks at Kayak published their data and most of it confirms what earlier studies had found. But it also offers more specifics on different regions. It’s important to consider that Kayak.com mainly does business in the United States, and it appears that their data reflects airfares starting out in the US. Still, the overall trends are likely very similar for flights starting from Europe or most of the rest of the world.

Kayak’s 2015 data:

• Domestic: Book between 4-6 weeks out
• Europe: 6 months weeks out (discussed further below)
• Asia: 5 weeks out
• South America: 3 to 6 weeks out
• Central America: 4 to 5 weeks out
• Africa: 2 months out
• Caribbean: 2 to 4 weeks out, but unlike all other regions, you can still get a deal one week out (i.e. it’s a great last-minute destination)   "

What does this mean to those attending Plunge?

• The best time to buy your airfare is anywhere from the first week of March to the first week of April. 
• If you buy before then you might pay a little more or maybe a little less.
• Avoid buying after April 1rst, you're more likely to pay a "foolish" amount for your ticket.   
• The worst time to buy would be after April 15th (Tax day in the US) You'll feel doubly screwed!

No matter what you pay to get there, by the time Plunge is over, you'll know it was worth it!