Archaeologists say they\'re preparing to muck out a salvaged 13th century Chinese merchant ship currently preserved in a giant water tank so they can study it. The Nanhai No. 1, which dates to China\'s Southern Song Dynasty, was lifted from the seabed of the South China Sea at the end of 2007 along with much of its cargo, China\'s state-run Xinhua News Agency reported. The State Administration of Cultural Heritage will decide on the final excavation plan for the wreckage by the end of the year, said Huang Liusheng, deputy chief of the Marine Silk Road Museum in Yangjiang in the southern province of Guangdong. The wreck of the Nanhai No. 1 is immersed in a purpose-built sealed tank in a 500-foot-long pool at the museum, filled with sea water and silt to replicate the water temperature, pressure and other environmental conditions of the vessel\'s previous resting place, officials said. Complete excavation and research on the wreck could take dozens of years, Huang said.