HPB of course does have some very definite statements on Atlantis. I will be getting to those. In my opinion, though, there is much material that should be covered to do HPB the justice she deserves on this subject. I would like her to receive that justice. So as part of working up to her view, I will be first answering your questions as you framed them.
You asked about the Carribean as a site for Atlantis.
Background: Fidel Castro was attempting to raise funds by looking for shipwrecks with treasure aboard that are within his territorial waters. He hired the high tech company of Advanced Digital Communications (ADC). Paulina Zelitsky is associated with that company.
On May 14, 2001 Reuters reported about her companies discovery off Cuba:
"Most intriguingly, researchers using sonar equipment have discovered, at a depth of about 2,200 feet, a huge land plateau with clear images of what appears to be urban development partly covered by sand. From above, the shapes resemble pyramids, roads and buildings."
This of course is exciting sounding material. I was looking forward to a significant find. Even though HPB (Blavatsky) asserts Atlantis was in the mid Atlantic - it could still have outposts at Cuba.
The Reuters release further said:
''It is stunning. What we see in our high-resolution sonar images are limitless, rolling, white sand plains and, in the middle of this beautiful white sand, there are clear manmade large-size architectural designs. It looks like when you fly over an urban development in a plane and you see highways, tunnels and buildings,'' Zelitsky said.
''We don't know what it is and we don't have the videotaped evidence of this yet, but we do not believe that nature is capable of producing planned symmetrical architecture, unless it is a miracle,'' she added in an interview at her office at Tarara, along the coast east of Havana.
This became extra interesting because Andrew Collins had recently written an excellent book that deeply researched old documents to find traces of knowledge of the western hemisphere in the old world. This led him to be the first to predict Cuba as the location of Atlantis. So the Cuba find of Zelitsky directed the spotlight of attention to his book "Gateway to Atlantis"
It has been more than three years now and I have not heard any further positive result. Maybe others have. But there is a negative result. There is another book "The A.R.E.'s Search for Atlantis" by Gregory and Lora Little. It is an excellent book and I expect to say more about it later. In that book are two quotes: "Sonar images can be very misleading, and wrecks and debris can be mistaken for structures." (p 60). Zelitsky had been using Sonar. And "In other cases, the sonar picture is far more geometrical than the anomalies appear to a diver." (p62)
What we discover is that Zelitsky subsequently took video of the site to supplement her sonar data. She then showed that video to Collins. Now if that Little book is read it becomes clear that it properly reflects the views of Collins. Collins wrote the introduction for it. That book also says "Initially, ADC utilized side-scanning sonar to discover the "ruins," but later they sent a small remote camera into the fast-moving, murky water. After viewing the video footage ADC sent him, Collins was unconvinced that the stone features discovered by ADC were actual ruins. To this writing, [book published in 2003] no new information has been released by ADC, and the world awaits the eventual outcome."
So here is the rub. Collins has much to gain if the Cuba site is verified. However when shown the video he was "unconvinced". So now more than 3 years later I am skeptical of the bold original claims.
There are also some theoretical problems with the Cuban theory. Cuba is not under the sea. Part of the alledged plain described by Plato in the dialogues as pointed to by Collins is indeed underwater. But other parts of alledged Posoidonis are above water. That is not so suitable for an island that Plato says sank "in a day and a night".
Here is a key passage from Plato:
"This power came forth out of the Atlantic Ocean, for in those days the Atlantic was navigable; and there was an island situated in front of the straits which are by you called the Pillars of Heracles; the island was larger than Libya and Asia put together, and was the way to other islands, and from these you might pass to the whole of the opposite continent which surrounded the true ocean; for this sea which is within the Straits of Heracles is only a harbour, having a narrow entrance, but that other is a real sea, and the surrounding land may be most truly called a boundless continent."
A shocking note here is Plato's reference to "a boundless continent". There is wide agreement that the reference is to the Western Hemisphere. But isn't that startling that Plato should know about that? (It would not be shocking according to some of HPB's statements.)
Also note that Plato is quite aware here of the distinction between the Atlantic and the Mediterranean. That decreases the viability of the arguments of Galanopoulos.
And finally this passage reflects negatively on the arguments of Collins. He makes much in his book of the greater and lesser Antilles. But in his case of Cuba those islands lead TO his proposed Atlantis and not FROM it as Plato mentions.
So, Brian, grand conclusion: Likely nothing Atlantean has been found in Cuba. I'll keep an open mind though. And the details of Collins' argument, while very well done, don't satisfy all the requirements.