A friend of mine has the Canon G11 with the proprietary housing. This housing does not have a threaded port or any other mount for wet WA lenses.
I have boosted about how much a good WA lens would do, hower with this housing what are his options? With an adapter there should be a selection of fish eye and rectilinears avaiable?
How about the "BigEye Lens G Series", he got an offer to buy a scratched one, but these does not seem to be that wide.