Yes, it does have a beach on Testlive! You should know that on every PvP server this seamount SE of Costigan’s Bluff is occupied. It’s value is that it is surrounded by water, fairly tall with straight sides. So it becomes a pain to raid. Certainly not un-raidable. I was raided many times while building it and of course the PvP hackers completely decimated it on several PvP servers so I quit Siptah PvP. It is just a bad map for survival PvP. No good base locations like on Exiled Lands map.
On Exiled Lands you can build in the many caves and ruins. Nothing like that on Siptah so I play PvE-C there. Siptah is like carefully constructed to be a waste of time. Might as well just build a shack on the beach and call it good, but trying to build up your character’s resources is a waste of time. You will lose everything every week.
Anyway, putting a beach around this seamount is going to annoy many PvP players and may destroy their main bases. Myself, I am PvE-C so I will just move since it is no longer a sea base, but I have quite a castle there, just has no aesthetic anymore.