Skirmishing under rain and wet areas? Even in summer, you will need something to protect your helmet cam from water, especially in the UK. It's available at Action Cameras for £32.99, though you might need to paint the bright yellow areas with a darker colour, they might  make your head a very attractive target by other players.

"Protection from the elements for your ContourGPS, our Waterproof Case locks out moisture while still allowing fully featured operation (including single-slide record and laser alignment.) Two safety latches keep it shut tight, and the TRails™ allow it to slide and lock on a variety of mounts. Fits the ContourGPS only."