The volcanic islands of Sebesi and Sebuku are located approximately 20kms north-east of the Krakatau volcano complex. Located only around 10kms south-west of Rajabasa volcano in Lampung, it is by far nearer to the shores of the southern tip of Sumatra, than to Java. From the small ports in the western part of Java, such as Carita or Paku, the islands can be reached in about 2 hours of speed boat ride, depending on the current in the Sunda Strait.
A typical one day trip starting at 7am from Carita will get you two dives around Sebuku and Sebesi, arriving back at Carita around sundown. A live aboard trip of 3 days is probably the best way to explore the area, as this kind of trip can include dive sites around Krakatau as well, and maybe Ujung Kulon. Or perhaps, because in Sebuku the attraction is the wreck of a Dutch destroyer Evertsen which was gunned down by the Japanese on the same day and the same battle as the Australian cruiser HMAS Perth and the American cruiser USS Houston laying in Banten Bay, a diving cum WW II historical trip could be arranged to include all three wrecks.
The two islands are not yet very popular for diving, probably due to their relatively far locations from Java (though it is quite near Sumatra). Other reasons could be that apart from the Evertsen wreck, there are no other dive highlights in this area, therefore people prefer to dive around Rakata or the young and active Anak Krakatau further south. However, these islands could provide an alternative to the Krakatau volcano complex dive sites.