RE: Help - Water in the hole!
Putting your board out in the sun surely won't hurt it unless you have an all EVA deck (GO-Rio-Start) in which case it might cause the deck to fade a bit.
If you know anyone with a vacuum pump, a partial vacuum (not a full one as that could cause the board to "implode") will lower the temp at which water turns to vapor and get the max. water out of your board.
Simply screw in a fitting in the vent plug, and put a partial vacuum on the interior of the board. The water and water vapor will be scked out but be sure to use some sort of catch can or vacuum filter to prevent the water and vapor from getting into the pump.
Check out: this link and work with Eva to get the right amount of vacuum to get the max. water out without any risk of "implosion".
Here's the link to the Eva Holliman's site:
Here's another link to how to get water out of your board without a vac. pump.
There's some really good info here on how to dry out your board.
Phill's offer of a dehumidifier is a good one. The dryer the air in the "chamber" were you are drying out your board, the more complete the process can be.
Hope this helps,