: not a big difference except that the 1 1/2" u-bolts are thick and
: chunky and long, I was looking at less than a half circle sitting above
: deck.

You might find a smaller gauge U-bolt which would not be so thick and chunky, but don't dismiss the length of these. The longer they are the better they are held in place by the endpour. What good is the thing if it is not securely anchored?

You might also look for an eyebolt which has the eye welded closed. It is basically a ring on top of a bolt. The length of the bolt also give an advantage in secure mounting, plus you can thread on a nut and a washer to spread the load. You can still mount something like this in a groove, as you propose doing with a ring, so that only a portion of the circle is exposed.

Just a thought.

PGJ