What mode do you use?

[Wild_Diver]

I know it is a stupid question, but I really have no idea.

I used to set to underwater mode to add some more red when I don't use any flash

but should I still use the underwater mode with my flash on?

Heard some people set in cloud mode, or should I just use auto?

really have no clue.

 

[Storker]

I guess that by "mode" you really mean "color balance", eh?

IM(NS)HO, there are only two sensible approaches to correct color balance when shooting in ambient light:
If you're shooting JPEGs, use manual color balance. Bring something white or neutral greyand set color balance at the depth you are at from that neutral thingy just before shooting. If you don't know how to set manual color balance, use auto.
If you're shooting raw, forget about color balance while shooting and set/tweak it during post-processing.

If you're using a strobe, select daylight or flash color balance.

 

[Ardy]

Try it in Program mode (p) first and see if you like the results. If you are happy use that for a while then try manual (assuming you have a man setting). It will take a couple of dives to get the hang of it but once you have mastered it you can use any camera underwater.

In Manual start off at F8 @ 1/60th for close fish shots and then adjust around this reducing F stop (5.6/4/2.8) for shots further away and increasing (11/13/16/18) for things closer. You can then start trying different shutter speeds and f stop combinations. Buy yourself some video instruction on using digital cameras and you are on your way...

 

[BlueDevil]

With my Canon I always set to underwater mode and get pleasing results. It also works fine with the flash so I just put on 'underwater' and leave it that way for the whole dive.

When I have tried manual white balance I have not be happy with the results - greyish appearance to the photos.

Of course it may be different with your Olympus.