Tank bag, GPS and video

[Mouse]

I've got one of those Oxford Sport tank bags, amd it is pretty waterproof (without the cover) except in a real downpour. I think the zips are the weak point that water gets through.

 

[DCB]

 

[Dinger]

I know nothing about cameras - can you buy those filters in different sizes (diameter)? Or will I need to bodge it?

LOL, why stop now Mouse?
Sorry, keep it up it's great.