I just did a pool lighting design a few months ago. Try to specify gasketed fixtures that are rated for use in a natatorium. If the fixture's cutsheet doesn't mention it then contact the local lighting rep and ask them for more information. Use PVC for exposed conduits.
Indirect light is more comfortable to occupants. If you use this then make sure the ceiling is white or your energy cost will go up trying to get the light levels you want. If there's upper seating or viewing then avoid blinding them with the uplights. Typical systems use HID lamps for the primary light source with suplimental fluorescent for emergency.