Create New Area Feature(s) from Selected Island(s)
With the island feature(s) selected right click to open the Digitizer menu. From the Advanced Feature Creation Options submenu, select Create New Area Feature(s) from Selected Island(s). This will launch the Modify Feature Info dialog for the new area feature(s). Specify a layer to add the feature(s) to and click OK to create the new area feature(s) from the islands(s).