Anchoring in the water under bridges can be dangerous
--some boaters ignore the no wake zone around bridges
--there's often sunken or piled up brush that an anchor can get snagged on
--waves are amplified in bridge areas
If you can, drop a mushroom or similar styled anchor in 0-6fow, then fish the pilings you can
If you want to fish deeper, first sonar scan the area to see if there's any sunken objects that could cause an anchoring issue.
If not, drop a mushroom or similar styled anchor
I have tried looping a brush clip around the pilings, and it works OK. The loop around the piling will tend to slip down into the water.