is one piece episode 305 filler?

Lucci is nearly unconscious after being hit by Luffy's Gomu Gomu no Giant Pistol, where he reminds himself that he can't afford to fall into the water. He then lands on a ship of the Buster Call, where the Marines are confused and amazed.

On the island, Zoro, Sanji and Sogeking (who is carried by the former) are running through the tunnel seeing that the water is reaching them. But the water appears from the other, where it also chases Nami, Chimney, Chopper and Kokoro.