Powder Point Bridge

[Bonefish]

I have a question. I was fishing lazily on Thursday night at the change in light. I was with a friend and we were chunking herring. My buddy had two immediate hits but was unable to keep them on. With that being said, I had none to that point. It was about 8:30 PM and I had a bobbing on my line. I was using a sand eel rig because it was easy and I had already made it. The leader was 50lb mono with two loops with standard hooks and a 3lb weight at the bottom. After those tugs I tried to set my hook.; It worked; I had hooked up with some sort of giant. I fought the fish for 7 minutes without moving my position on the bridge. I did not check my drag prior to my outing. After fighting this fish and seeing how much drag it was taking I thought it might have been to loose. So I tightened it and quickly realized that my drag was right from the beginning and if I did not return it to it's original position I would not be able to hold onto my rod, let alone the fish! I returned it. Fought the fish on another run for 3 min. it seemed to run out of steam. With several people standing beside me and 200 yds to the end of the bridge where I could land it, I tried to tire the fish out in the hope that I could eventually drag it to the right to the beach and land it. The behemoth surfaced for a brief second as the crowded went crazy, it was easily a trophy-sized bass that would land me on the front page of the famous "Striped-Bass.com". It took another dive and my leader broke. I have yet to scan the picture of the leader but it broke off a double 50lb mono line. My question is how should I have handled this fish differently? I tried to turn the fish to avoid the line scraping on the sides but it is difficult on a bridge. All the while trying to keep it from the abutments. I also would like to know the best ways to land a fish if fishing from a bridge. I have heard of people rigging a fish finder to drop a treble hook to the fish once it has been hooked to drag it up, but this fish was to big for that setup. I feel like I have missed my chance for my 50lber. Any help on how to avoid similar issues and problems in the future would be helpful. See you on the beach!