Another social networking site for sailors

In the last two weeks I have blogged about two sites that I over-enthusiastically called "Facebok for Sailors".  I need to be a better self-editor! First there was Boaters.tv, a video podcast that will eventually become more of a social networking platform. Then there was Sailtrac, a Google maps mash-up with a Facebook-like community. Well, I just heard about a third one called Tripsailor. It's a German-based site (I think) in the very early beta stage. You can see their vision in this prototype page about sailing in the Baltic. I really like the simplicity of this site. It seems easy to use, share stuff in different media and if they get it going like Facebook it could be very successful, but... ...that's a pretty big if. While I hope they all succeed, I am not sure that the online community of sailors can accommodate three social networks. Each one has a different tack (no pun intended): Boaters.tv combining a video magazine and a community; Sailtrac, a good mapping app and Tripsailor a simple Facebook-like interface. My concern is that the online sailing community is still quite small - maybe in the tens of thousands. It's exciting that the online sailing community could be expanding beyond blogging into a broader and even more vibrant community. My question is how will these three (and I am sure there will be others) will support themselves and build critical mass? What does everybody else think?