I also have a Fujifilm underwater camera, model WP33. Some of my best tank shots are taken underwater.
- Have you tried shooting with the Forced Flash?
- Have you experimented with the Shooting Mode? That is where you can choose: Auto, Natural Light, Beach, Snow, Nighttime, Fluorescent, etc. There are about 20 different settings. In "real" photography, I believe this is called "white balance" and with these cameras probably involves automatic F-Stop adjustments. (Mike Savage and others can tell us more about that.)
- Have you tried pressing the shutter button half-way down to focus the shot first and then moving closer? Sometimes the camera wants to focus on the glass, especially if it's not clean. Moving closer after setting the focus overcomes the cameras tendency to focus on the glass. Also I believe it becomes more of a problem with fluorescent lighting.
Funny thing about flourescent lighting. It tends to give a hazy appearance. I believe it's because the light is coming from so many directions out of the flourescent tubes. It even makes clear water look hazy because of light refraction.
Here is an underwater macro pic in the Natural Light mode. In this situation I have to deal with distracting bright sunlight coming from behind the subject.
That's all I can think of. Maybe Mike Savage and others more experienced than me will see this and chime in.
Aloha