underwater camera

I am getting the Reefmaster dc500 and wanted to know about getting a strobe.
Many years ago I bought a housing for disposable cameras and a strobe, but I
needed it as the disposable camera flash was pretty worthless. I then had a
point-and-shoot camera in a pressurized case (a Reefmaster camera) and just
used the built in flash, and the pictures were just fair. But now with
digital cameras the electronic ISO settings will, I think, be better than a
film camera. Of course a strobe is much better than the built-in flash, but
how necessary is it for someone who is not a professional and not diving
more than once a year?

Thanks!!

Eddie G