Thanks for the reply, I have been using the ziplock method inside the chinook. Unfortunetly the seal is torn badly at the corners and is ready to be retired.

I think i am leaning toward the sealine with the rool top and velcro. i am also thinking about throwing a couple of those little dessicant packets that come in electroincs and various other products.

I normally take a fisher map and canadian topo. Since they are different scales I can flip back and forth from one side to the other with out opening the case on the water. I use the topo to log wildlife, plants fishing structure, eyc. On the fisher I mark campsites, portages, sandy areas etc.  
You can use a sharpie mark on the outside of the map case then wipe it off at camp after you transpose it to the map.

Its great for reliving previous trips :)