I found a fly box today that is just about perfect for boat/float fishing. It is the Orvis boat fly box ($39 but I got it on sale). Here is a link http://www.orvis.com/store/product_choice.asp?pf_id=73X0&dir_id=758&group_id=15072&cat_id=5135&subcat_id=6030. The box is nicely water resistant but not fully waterproof. I’m not trying to market for Orvis but for me this box is exactly what I was looking for.
I too have been wanting a big boat box for bass/lake fishing. I wanted to have all my bluegill/bass/carp flies together in some “big-old” light weight setup (I use a smaller pocket box if I’m wading but a big boat box was needed). I love my Bugger Beast, either original or homemade, but it really is too big to hold the little bluegill flies and jigs. I really wanted a big box that could be a clearing house for my go-to lake flies.
It is very large and holds big streamers and poppers on the right and it has a separate box for smaller flies on the left.


I put all my bluegill/crappie flies on the left (could easily hold about 150 flies)

Big meat and poppers on the right, could easily hold 200 or more flies.



On the left lower section they have a magnetic strip and two pockets but I modified this by gluing a magnet on balsa wood and glueing foam on to that. Thus I have a “removable” fly holder to dry flies throughout the day.
Orginal left-bottom

Modified with an extra fly station
