They lose the innertube

While walking to the beach, a sudden wave knocks over both Chiaki and Ibuki and knocked the innertube out of their hands.

With their quick reactions, the two girls try to grab it, however, all they ended grabbing was each other as they fall into a compromising position.

Both of Ibuki's hands were on Chiaki's breasts and Chiaki had both of her arms wrapped around Ibuki's body. Ibuki accidentally squeezed Chiaki's boobs causing a small mone, something that Ibuki didn't mind. Chiaki started to feel a sensation as Ibuki's hands held her breasts, Chiaki's boobs were sensitive to touch.

Now the two were naked with no cover. Do they go back for the innertube, do they go for the towel or does something else happen to make things harder for the two?