Two Major floods Ikelite Housings D70 first when I was ignorant and starting with DSLR Port oring poorly seated.
Second D300 Ikelite Longest port with Sigma105 in a current holding line on surface think it banged on something and was nearly full at 5M.
Also a self serviced G1 Ikelite housing (checked without camera) failed to seat most button orings water poured in so fast I had to do it again to see which ones were leaking (no electronics in that housing).
Now I have Bill's (Underwater Camera Stuff) vacuum checker no leaks but two false alarms from the electronics probably due to temperature change (I now vac the housing to about 1 psi over where it goes green, that seems to be enough). AND one genuine warning of a poorly seated oring that would have drowned camera. So I'm definitely ahead on that. Although this showed up when failing to pressurise at all so electronics not needed on that occasion. But I like the green flashing lights!