Although it looks like Hoppo can swim normally so can her I class
Jarlath said:
That I-class is a pool toy. Haruna, though...
Presumably they all can, so long as they aren't using their shipgirl powers (Hoppo: "...you shouldn't use your shipgirl powers..."). Haruna did so accidentally too, as she said.
The left end of the leftmost sound effect in panel 4 is slightly clipped off. Edit: Also, that same panel is the only one in which the I-class pool toy's eye isn't colored green. I'm not sure if those are worthy of the "error" tag or whether the artist will notice them and consider them worth posting a revision.
Kaga. Nagato. You two need to learn to not turn fish into charcoal. Moderate your fires, girls.
I thought the issue was that Akagi blasted both of them, as they were obviously ready to use the infamously phallic swan-swimming rings to join in with the rest of the kiddos two panels before. Granted, all three changed outfits and both Nagato and Kaga's are singed/covered in soot, so it might be that Akagi bopped them and then they failed to cook saury.