is one piece episode 388 filler?

As the Flying Fish Riders make their initial flyovers of the Thousand Sunny, Luffy grabs onto one and throws its driver off, going on a joyride. Sanji easily kicks away the first drop of grenades toward the ship.

Nami orders the sails raised, but the battle is almost stopped dead in its tracks when the fish make their first dive to regroup; they can only stay in the air for five minutes at a time. This puts Luffy underwater, and he starts drowning.

Chopper and Brook jump after him, and they drown, too. Franky and Nami have to save all three.