The Water Seven Saga is the fourth saga of One Piece, divided into four arcs: Long Ring Long Land, Water Seven, Ennies Lobby, and Post-Ennies Lobby.
The Davy Back fights were a cool idea. However, I wasn't a huge fan of Foxy, who in my opinion was just a cheap knockoff of Buggy. The Davy Back fights dragged on way too long in the Anime. However, the ending was incredible with the introduction of Aokiji.
Basically a setup arc for Ennies Lobby, but there was just so much happening in this short amount of time. Luffy vs Usopp, CP9 reveal, Robin's betrayal, and so much more. Incredible arc from start to finish.
Many storylines built up in the previous arcs culminate here. Again, so many great moments, from Robin's backstory, Luffy vs Lucci, to the farewell to the Going Merry. One Piece's finest hour.
The arc does everything in its short amount of time, from Blackbeard vs Ace, the reveal that Garp is Luffy's grandfather, and of course the reveal of their new ship, the Thousand Sunny.