For ocean I like the nautical charts for the traffic channels, buoys, lighthouses, markers and local features you wouldn't see on any other map. Also keeps me out of the mudflats and dead ends at low tides.
My experience is also that trips are kind of few and far between on this site, I'm thinking that the new meetup page will be a great resource for organizing such events, I know I check it frequently for many kayaking groups. I do appreciate more experienced paddlers taking me "under their wing" and showing me some great spots. Phil