The long tracks are all from various singles he released. Interludes were placed in between each giant slab as a way for the listener to catch their breath, from high to low breathing. But these fit in quite well with all the bigger pieces, like filling in the cracks.
“Oarca” has a submerged beat. It is so slow and meanders on the absolute bottom. “Acqua” presents itself as a more traditional, longer burning jam. Even the start suggests that the song began before we were listening. Finally, the epic closer “Riva” starts with the closest Sandro gets to distortion and a full rave-up. It is really quite a wonderful ending, appropriate considering the emphasis post-rock places on the end.
Yeah, the sea-references are deliberate. Apparently this was to have a nautical theme of some sort, and without having cheesy whale calls, it succeeds in that goal.