Wet WA lens for TG6?

Hi all! 

I have a TG6 and the olympus tough housing and love it for macro but would like to invest in a compatible lens for better wide angle shots. Would love to hear any recommendations

Thanks!

This is a review of the uw fisheye you asked about. Hope it answers yr questions.

ttps://havecamerawilltravel.com/olympus-tough-fisheye-lens/

You could try out the INON lenses, they have recently release one in M52 mount.  IT will give 95° field which is about 20mm lens equivalent  or you can add the dome which gives 140° field- the dome can't be added underwater though.  I haven't used them but they seem to have a good reputation: 

http://www.inon.jp/news/news583/

Thanks!!