Alan Morison, 67, the Australian editor of the Phuket-based website Phuketwan, and Chutima Sidasathian, a Thai reporter who covers the Rohingya refugee issue, had been facing up to seven years in prison on charges of libel and violating the Computer Crimes Act.
''We are extremely relieved to learn that Alan Morison and Chutima Sidasathian have been acquitted,'' Reporters Without Borders secretary-general Christophe Deloire said.
''Even in a Thailand ruled by the military, the navy should not be able to deter journalists from investigating and other journalists from quoting their findings, which incidentally did not target the navy directly.
''The attempt to torpedo this local website has failed but it has been hurt financially and the lawsuit will have a dissuasive effect as it could encourage other journalists to censor themselves.''
Deloire added: ''The Thai authorities must stop abusing the defamation law and the Computer Crimes Act must be repealed. These two laws constitute a permanent threat to media freedom in Thailand.''
The Royal Thai Navy brought its complaint against Morison and Chutima on 18 December 2013 over a paragraph in an article published on the website on 17 July 2013 that was headlined, ''Thai military profiting from trade in boatpeople, says special report.''
The offending paragraph was a quote from a Reuters special report that accused Thai naval forces of participating in the trafficking of Rohingya refugees from Burma. Reuters itself has not been sued.
Thailand is ranked 134th out of 180 countries in the 2015 Reporters Without Borders press freedom index.