When I've submitted articles to publications, as I have on occasion, they've generally required that I sign a boilerplate "transfer of copyright" document, or some such. Basically, they require that I sign something that says I'm giving them the rights to what I've written for them. This is true of technical (scientific) publications as well as whitewater magazines; it's true of online publications, as well as those that end up in print.
When I post to Boater Talk, there's no notice that says that BT or its owner gets the copyright (not that I've seen, anyway). If there's no agreement that says that the writer gives up his copyright, I can't see how Eric can legally assert copyright ownership. It's a moot point, of course, as Eric doesn't act as though he owns the copyright. (For instance, he flat-out says that he'd contact the author if someone asked *his* permission to use info found on BT.) However, on this fine technical point, it would seem to me, a layperson with an opinion and a big mouth, that the author owns the copyright.