Side-scan images posted previously; Steel (or iron) hull, deteriorating of course with a few big holes in the hull; Pointed on both ends; No drivetrain that I could see; If there was a prop or rudder they were in the mud; Some wooden decking.
Large log laying at a right angle across the gunwhales, not tied down, as if it might have been used for ballast but I don't understand why someone would use such a thing. How it got there I don't know. Shadow on side-scan image from the log had me wondering until I dove it.
Bad location to dive as the traffic is heavy. Sophie C traffic etc. is one issue-the other is the Mount. You WILL be in the way if she is coming or going.
It has been suggested that this might be a Liberty ship lifeboat, as they apparently were steel and were known to have been converted to steamboats.
http://www.youtube.com/watch?v=oFkK44Jkzaw
Video by Lea Nichols.