Just to clarify, you actually had the lights on and started changing modes while submersed?
I only ask because the IPX-7 and IPX-8 ratings refer to water-immersed lights at specific depths and times, but do NOT cover actual activation or use. For that matter, they technically still allow water ingress, as long as it produces "no harmful effects". It is thus quite possible to pass IPX-8 testing (done with the light off) but have it fail immediately if you press the switch.
This is an important point, as people read too much into IPX ratings (i,e., the actual standard is not consistent with most people's intuitive understanding of "waterproof"). Only dive-rated lights are guaranteed to operate underwater without issue.
FYI, the ANSI FL-1 standards of "waterproof" and "submersible" are slightly more stringent than the IPX-7 and IPX-8 (upon which they are based), but even they don't cover lights in actual use - only submerged lights in the off state. Unfortunately, all bets are off if you turn the light on while submerged.
