Have now ordered my new underwater housing, my dilemma is this was after a 14 mm
but lack of stock anywhere there are a few other options.

Canon EF 15mm f/2.8 Fisheye
Canon EF 20mm f/2.8 18
Canon EF 16-35mm f/2.8 Type I & II
Canon EF 17-40mm F/4 1
Sigma 14mm F2.8 EX
Sigma 15mm F2.8
Sigma 15-30mm F
Canon EF 100mm f/2.8
Sigma 50mm F2.8 EX MACRO

These are the only lenses for the housing eg gear and dome
As I have not used these any of these lenses recommendations or pro and cons gratefully appreciated.
Thanks
Stu