A few you missed. I've waterproofed several land machines and also had most of the ones listed below. Waterproof cases are necessary with all the humidity and rain we get, but as far as a dedicated water machine, I prefer the Excal, CTX, and NOX.
FISHER:
CZ-7
CZ-7a
CZ-7a Pro
CZ-70
CZ-20
CZ-21
Impulse
MINELAB:
Excalibur
CTX
WHITES:
Beach Hunter ID 300
Surf PI PRo
Dual Field
DETECTOR PRO:
Diver
UW-12
PULSE
GARRETT
XL200
XL500 VLF
XL500 PI
Sea Hunter 2
Infinium
ATX
TESORO
Sand Shark
Tiger Shark
AQUASOUND
(Multiple)
JW FISHER
(Multiple)
Note: I included the FIsher CZ7 series due to them being rated as splashproof. The housing is completely sealed so a deluge of rain and rogue wave do not affect it, but it can't withstand significant pressure....the headphone isn't mechnically sealed.