Dig around the rocks and under the mussels, when you find one, stay in that spot and widen your hole as well as go deeper. They will be anywhere from an inch to 4 inches under. You don't need to go deeper than that.
Hey man...its really easy to get to the wall...its a great spot to go for a relaxed dive. I work in Narragansett and I dont get out until 5 so it allows me to get in some good diving before it gets dark. Honestly the best way to find it is really to google the coastguard house which is a restaurant. you will see the big wall there usually a bunch of people running, biking along...Once you are at the Coast Guard house you want to follow the wall all the way down to the right until it ends. You will run into a little jetty/pier that jets out into the water(this can be seen from anywhere along the wall). The pier has parking on it and is perfect for getting in the water. Then ill usually follow the wall back down towards the coast guard house and then turn around returning me to Monahans...You can find lots of totaug and the occasional bass here...if youre diving 10-15 this spot will be perfect for you...