From their website:
New single bases in Gale Force Nine’s series of Fleet Bases for Axis & Allies Naval Miniatures are now available in the GF9 Online Store. Now you can purchase Fleet Bases from our forthcoming sets for Task Force, Flank Speed and as an added bonus, the new War at Sea Starter Set! Now you can base your entire collection.
Find these new Fleet Bases and our entire line of Axis & Allies Naval Miniatures accessories on our online store and look for our Fleet Bases Sets in your favorite game & hobby store.