Tourists marooned on Thai islands hunkered down Friday as Tropical Storm Pabuk struck the kingdom, forcing airports and ferries to close and bringing power blackouts, heavy rains and massive sea swells.Boats were recalled to shore across the Gulf of Thailand, while three key southern airports were shut until Saturday, leaving tourists who remain on islands now cut off from the mainland."Ten thousand tourists are still on Koh Phangan," said Krikkrai Songthanee, district chief of the