Handcock states that only 500 submerged sites have been found worldwide containing the remains of any form of man-made structure or of lithic artifacts... Of these Int'l sites, only 100 are more than 3000 yrs old.
Earth is a continual rise and sink of continents, & waterways... And hidden beneath, are lost civilizations; unlocking the keys to land transformations.
Two excellent videos (part 1 & 2) amidst activity in Pacific "Ring of Fire"...
Part 1: BIG SCREEN VIEW (new window) HERE.
Part 2: BIG SCREEN VIEW (new window) HERE.
Of the Pacific Ring of Fire's submersed volcanic land-mass... 1500 active volcanoes (80%, or approx. 1200) are in the sea. VIDEO.
In 1997, a chain of mountains almost 2000 kilometres long and more than 3000 metres high was discovered in the South Pacific. Nobody ever knew the mountains were there before because they are under water - as, in fact, is 70 per cent of the earth's surface...
In the case of continual expansion & weakness of the Pacific fault-line... I believe parts of region's underwater land mass will eventually surface.
On land it is obvious that archaeology still has much more work to do before it can honestly claim to have fully understood (rather than merely theorised about) the process by which the great civilisations of ancient history arose.