Green bridge is my favorite spot, very sprawling and plenty to see on multiple dives. Kings beach is also good, get on the seaward side of bird island and you can get so really good diving. Inside the island is more protected and is a nice beginner dive.
Land’s End is a great spot, but parking is a hassle for people without a permit hi usually off load gear and park at a bird sanctuary a mile away and walk back. Not particularly deep, lots of good topography, plenty of fish life and better than average RI shore visibility.
Ft Adams I have never been that excited about, boring topography and right next to main channel.
Beaver tail has some good diving, I have been to the site shown in the Aerial photo, wind and tides are critical. Hour before high tide, and in the lee of the wind. Your exit point is small and you don’t get many option to get out. Being close to the southern tip of the island, next stop block island if get caught in a current.
At parking lot 3 on the other side of beaver tail there is also decent diving. Again, it is exposed, so pick your dives carefully. Being in the lee of the wind will keep you from getting the stuffing knocked out of you on entry and exit.
Narragansett has some interesting spots. Always been meaning to swim out to the barge off the town beach, but never got around to it. Max depth 15-20’.
Narragansett pier is was a popular spot for training dives. I have only done couple of dive there and was never super impressed.
Hazard ave is a really great dive dropping off to 50’, but it is named that for a reason. Really have to plan you entry and exit strategy carefully. I dove it in college and went back to look at it a few years ago and decided I was stupid in college....
Bass Rock (Narragansett) was a fun dive, shallow but interesting. Lots of portage of gear over large boulders.