If you want to go below 130' or attach strobes to it I would say "yes".
If you want to attach a lens to it, it won't work on the G9 no matter which housing you go with- need to look at a different model to that.
If your freediving/spearfishing I would just stick with the Canon case- smaller, lighter, cheaper.
Just my $0.02- adjusted for inflation.
Jon
