Hello everyone,
Here we are for yet another review of a rather recent anime series named Kenkou Zenrakei Suieibu Umisho (from here on, abbreviated as Umisho) that aired in 2007 based on an original manga by Mitsuru Hattori.
Let's start with a synopsis :
Kaname Okimura, a student of Prefectoral Umineko Shougyou High ("Umisho" for short), joined the school's swimming club in order to learn how to swim, but the club is filled with weirdos, let alone teaches him swimming. Then, a sunny, happy-go-lucky girl named Amuro Ninagawa who was transferred from Okinawa joined the club. Her extraordinary underwater speed and unorthodox swimming style surprised every club member, especially Okimura, because she reminds him of a mermaid-like creature he saw only once in his early childhood
Yes, this series starts up like a comedy fanservice series and continue to be it for the whole run and that is a good thing. (no random drama moments like Kore wa Zombie Desu Ka)
The story is by itself very simple based on the clichè of the club activity (this time the swimming club) with all the hilarity and fanservice you can get out by a situation with plenty of girls in bathsuit.
While the story focus a lot on the fanservice it is not disturbing (no, no Seikon no Qwaser here) and the comedy present almost everywhere makes the whole series very enjoyable.
The story have an episodic approach for most of the series even if all the episodes are highly linked and take you toward the final competition that the club will challenge at the end of the series.
The anime series does not have a satisfying ending (as the manga was still running at the time), so if you are looking for the real ending of the series you'll have to look on the manga. (Which I plan to get sooner or later)
The characters are many, but except for the main one the other are very difficult to remember as they don't stand out too much. There is no personality growth in the characters.
My favourite characters is by far the beautiful Mirei Shizuoka, I love how she is self-conscious of people looking at her and how she reacts at watching males. 
The graphical quality of the series is pretty high even thought the particular style used will take some episodes to adapt or well that was my experience. The animation is pretty smooth and there are no big problems.
The sound quality of the series is top notch as well with many famous seiyuu working on this project like Aki Toyosaki in Amuro's role, Ai Shimizu in Maki Ikuta's role, Ryouko Shintani in Sanae's role, etc...
Concluding, this is a rather enjoyable series with good production values and well done fanservice and comedy segments. I suggest it to everyone looking for some random mindless fun!
See you soon,
feal87