or just a photo type gift?
If you are doing a gift including photos how about a 12x12 scrapbook frame, this way you can make a 12x12 page with the photos mounted, a little journaling and leave spaces where you can place a piece of fishing net, a lure or hook or two, some little rubber wormy things. Add a couple pieces of rope around the edge and place it all in the frame. They are generally sort of deep, like a shadow box and come in several colors. I got mine at Michaels and have not used it yet but I will eventually.
If your scrapbooking the photos....how about plaid paper, a few solid colors to match the plaid you pick. Can you scan his lures? If so cut them out and mount them on pop dots for demision, add a straight cut border with some squares in the corner with fishing items on top. Keep it totally masculine and not kiddy.
Hope this helps.