Hanks water rating can and should be taken with a pinch of salt.
My dt8s screws on the bezel were not as tight as they should be and can come loose over time, ideally he should use some low tensile strength loctite and a slightly higher viscosity lube like super lube and ensure the screws are at a reasonable tension.
I do prefer the new screw on bezel for the switch. One of my D4V2s had a visible 1mm gap, fortunately I was able to pop it in the vise and sort it out but shouldn't have shipped like that.
I personally would never submerge my hanklights in water.