War Cast Studios have released a set of Deep Dish miniature bases with rounded edges.
From their announcement:
New Deep Dish bases with the fancy edged lip. These new bases are ideal for creating custom themes where you need some dimension and depth to your base. Perfect for adding green stuff or water effects when you are making swamp bases. Just add a mesh panel and get real depth from your sci-fi flooring.
These new bases are available in 30mm, 40mm, and 50mm. Look for them in our online store.