When I bookmark things in my folders for unread, partially read, or completed series, I give myself some sort of short summary of the characters or themes so I can get an idea of what the hell it is at a later date. This one got "the heroine is a boat"
I probably haven't even thought about this series since 2011 but that short, stupid phrase actually reminded me what the hell this is. My filing system might be more effective than I usually give it credit for.