Guides Choice Fly Box
It's big. It floats. There's no way you're getting this bad boy in your fly vest, and it's not going in your waders top pocket. I suppose you could give it to your dog or kids to carry around, but ideally you're in a boat for the day and want to make sure you're covered for every eventuality. That is, for flies.
This box is waterproof and holds hundreds of flies. It will fit all your big intruders as well as your summer steelhead flies all in the same box. Unless you're like me and tie way too many, in which case you'll need two! In any event, it's as cheap as you'll find for a great rugged waterproof fly box with quality foam, so go ahead and get Three! Two for yourself, and one for your jealous buddy carrying around all those other boxes.