No, there are no beaches on those two islands, making it impossible (atleast afaik) to get there with anything else but the Ragnarok.

And i just love that limit. But it seem to deal an jnreliable amount of damage. I used ot an some regular monsters in Ultys Castle, Adamantoise i think, and it only dealt about 5000 points of damage, whilst on the Ulty/Griever Boss, it dealt 15000.
Grantred the Adas has a high Defence but still......