Need advice for shooting in the rain

Im going up to scotland in a couple days and I think its going to rain for most of the time im there. :(. Apart from using an umbrella im not really sure what to do to keep the rain off of my cameras. An umbrella seems good, until I use a camera with manual focus. Then it's awkward.

I have a kiev 88 and canon eos 600D im planning on using so I dont think it will be quite as simple as buying one of those bags I put over the camera. Especially considering the kiev is shaped like a brick.

If anyone knows any good products or advice on what I can do to keep dry, please let me know. I would appreciate any and all advice on the subject. Thank you :)