The uninhabited island of Sveti Grgur lies between Rab and Krk. It dates back to medieval times when it was called Arta. There are steep crags on the north side, and it is overgrown in macchia. It is the northernmost evergreen Mediterranean-type island on the Adriatic. There are a number of interesting diving sites with a variety of interesting features. One is a deep canyon between Sveti Grgur and a high rock rising 3 m above sea-level and dropping to a depth of 30 m.
Descent starts in a pebbly cove and continues in the direction of the separate rock and on to the wall. The wall drops to 14 m and then 18 m where the point starts in the direction of Prvić, dropping to 50 m.
Diving continues across the tip, through the canyon in a westerly direction and then back along the right side of the wall, past the anchoring point and on to a submerged pyramid at 12 m, and then through a gap, along the left side of the wall and back through the canyon and to the cove.
Inhabitants include octopi, cuttlefish, gobies and crabs, with snails on the walls as well as scorpionfish and combers; lobsters can be found at 40 m on the western side of the submerged point. The area around the pyramid is rich in sponges, algae and soft coral, and brown combers rule over the crevices and holes.