Appreciate the suggestion but have checked the site and confirmed that Cateye describes that model as only 'water resistant'. I ocassionally drive in seriously heavy rain. Today I actually commuted in a shorty wetsuit and surf sandals and simply changed at work.

As a result I've drowned too many lights to be interested in anything less than fully waterproof. The units I'm currently testing seem to fit the bill do far.

There's a good weather seal on my Trek light. No problems with it.