I'm beginning to think that maybe those aren't islands at all...from here..
Sutek was on the same ship as Captain Johne, when it was sucked into the Underworld, but was spared from being killed, as his other companions were. Leaving Johne and finding a way back to the surface, Sutek built a house on Spektran and researched the Shadowlords
Maybe that's just the location where he got sucked up.....he fought his way to the surface and built a house on Spektran???? Where is that???
This was all I could find about Spektran...
Spektran - In Ultima VI, it was an uninhabited island where a group of pirates buried their treasure, including a silver tablet of the gargoyle language. In Ultima VII, the island housed the mad "Sultan" of Spektran