This idea came out of thinking about the tournament, but I was wondering if anyone else might agree with me. I think Nami's weather abilities should be able to harm Logias(at least some types), without needing Haki. Particularly her lightning should be able to damage some Logia types. It's not exactly something you can avoid by turning into an element. Caribou is a good example of someone I think her lightning would have been particularly effective against, since he's not exactly a typical Logia himself and swamps generally are pretty moist areas.
Maybe it's more like her abilities give her a better chance to exploit a Logia's natural weakness. For example, if she was fighting Crocodile, she could make it rain. Also, fighting against Monet here:http://www.mangahere.com/manga/one_p...0/c686/11.html, she was able to hurt her with her heat ball. Nami's abilities are powerful, and she definitely shouldn't be underestimated.

