Well I'd suppose it all depends on what you're looking for.
A very popular one is the Marine Museum - there's a couple of anchors and the reamins of a barge, along with muchos bottles and other junk to look at - depths to 40' or so.
There's also Morton's Wharf, a personal favorite of mine, although entry/exit can be a little tricky. It's a submerged L shaped wharf with lots of timbers, fish and other stuff to look at - and being at the site of a former distillery loads of bottles hiding in teh silt as well. Top of wharf at 6', depths to 30'.
Just outside of Kingston, off Howe Island, lies the
Cora W Post, an old barge that sank carrying a load of bricks, most of which can still be seen lying neatly stacked in her hold. Another fish mecca during certain times of the year, I'm not sure about this early. Depths to 40 - 45'.
There's also the Portsmouth Olympic Harbour which has two anchors, including one
rumored to have come from a German U boat (you decide), as well as the ribs and keel of some unidentified wooden vessel only 50' from shore in 20' of water. Further out, there's a line to another wreck. The Stacked Hulls are also diveable from this site; I have not yet personally visited them, and I have been advised to either carry LOTS of gas or prepare for a lengthy swim one way or another, and diving the Stacked Hulls during boating season is ill advised due to their location in the middle of the approach channel to the harbor.
So , yes, sure, there's lots of available shore sites in Kingston. If you want site sketches of anything I've named, or advice, please let me know!