The Umpqua UPG Foam Salt Waterproof Flats is a large, waterproof saltwater fly box for flats patterns and other bigger flies. Umpqua rates it IPX 6.5, and notes it can be submerged up to 1 meter. The latch closure is positive, and the clear lid lets you check what’s inside without opening it.
Inside, Umpqua’s Power Grip Foam is meant to hold flies tighter than standard foam. Magnetic swing leafs add quick-access storage without digging through rows. Capacity is up to 120 flies overall, or over 45 large flies. Size is 7.75" x 4.5" x 1.6".