I've started reading an older manga named nacuN. It ended in 2010 and it sounds like the translation releases are going to be sporatic but I found the first 12 chapters to be really interesting.
In the near future, an apparatus has been developed that can separate oxygen from water, thus allowing humans to dive for long periods. At around the same time, a brilliant, Nobel Prize winning mathmatics professor suffers a horrible accident which crushes the left side of his head, completely destroying his ability to use language or communicate. With his mathmatics career over, he turns to studying ocean life.
Eventually, he releases a "thesis", which seems to be nothing more than footage of dolphins. It's received with confusion and scorn. The academic world dismisses it immediately. However, a college student, after watching it many times, believes he's found something, which he hopes will make him wealthy and powerful. In order to understand, he decides to study dolphins, which brings him to a small, backward Japanese island.
The twelve chapters out now are mainly about him trying to fit in with the island folk, some of whom are not very friendly to outsiders. An island girl that is outcast from the rest becomes a particular thorn in his side, as she spends much of her time swimming with the dolphins he is trying to study. There also seems to be some shady activities going on with fishermen from a neighboring island and some mysterious foreigners with high-tech gear.
There is some nudity, though, oddly, only in the first chapter was it overt.
This is more of a story like you'd find in a novel than it is a typical manga, so it certainly won't be for everyone.