Assessment of underwater footings on rock

[Sjotroll]

Hello!
I need some suggestions, tips and ideas from someone with experience on assessment of underwater footings on rock.
A few days from now I'm going to dive around an old fortress founded on rock. The goal is to assess the condition of the foundations. Since this is the first time I'm assessing footings on rock underwater, I thought that maybe someone with more experience could give me some directives and give tips regarding what to focus on, what to look for etc. Of course I know the standard stuff but since it is a specific condition there is probably something that wouldn't come to mind at first.

Thanks!

 

[Guest090822]

I don’t know the rock strength or if the body of water is moving, but scour would be my focus.

 

[oldestguy]

Were they placed (poured) in water resulting in low cement content? Or bad W.C ratio.