Carrying a violin - Waterproof backback?

[Hathor]

What is the best way to carry violin to school in the rain? Is there a waterproof backpack-type cover that goes over a violin case? Preferably not costing too much.

www.thestringzone.co.uk/cases-covers-oblong-violin-cases-high-visibility-waterproof-case-cover-by-pedi

bit pricey maybe?

Thanks for ideas. I will try the camping shop rucksack cover.

Surely the case is waterproof anyway? I went through three or four violin cases over the years in various sizes and never had a problem with rain getting in.