To be completely honest, Umi would have no trouble at all carrying Honoka. The latter though, as energetic as she is, lacks the strength to carry the girl for more than five seconds. Lazy Honks is lazy. Though, if it were SID Honoka, then she could probably do it since she and Umi practiced Kendo. Anyway, this answers the 'who's the top and bottom of HonoUmi'.
I'm still trying to figure out why Umi didn't get pissed off when Honoka's feeling up her ass.