If you've purchased a Supernova E3 light, or are just about to buy one, a word of caution: the light is NOT waterproof if used upside down.
At least one randonneur who used the light upside down on a rainy brevet reported that it leaked and sent a note to the manufacturer. (He won't be the only one who installs the light upside down. While it's not obvious from the picture above, mine also mounts that way on the front rack.)
Gregor Arndt, who is the COO of product management for Supernova, confirmed in an email that a design flaw exists.
Here's what Gregor said:
I've talked to our designer and he admits the light was not intended to be installed upside down and still be watertight! The vibrations of the cable will lead the water into the housing. I am sorry that we have not mentioned this before, but we've had no previous experience with inverted installations.
As a quick solution, we recommend putting some black silicon around the cables where they exit the rubber seal. We will work on a permanent solution, of course.
In case of lamps that already have water in the housing, we recommend opening the front cap in a warm, dry environment, letting all the moisture evaporate. The rear of the lens may have to be cleaned with a moist glasses cleaning cloth.
If there has been any serious damage (which shouldn't happen at all, since all the electronics is coated), we will send a replacement.
In a note to the Trailer Park, Gregor thanked us for alerting E3 owners to the problem.
I just want to emphasize again, that it should be OK if you use some silicone sealant and that the electronics inside won't be damaged by water.
We will react to the issue as quickly as possible.
Gregor said he'd have an update in the next three or four weeks.