Been watching for years
I've been watching military bases on GE for years. It's really quite worrying to look at some of our naval ports (plymouth for example) and see the whole fleet in dock - makes I worry if a war be commin, all the navy lads ashore havin fun,
Jocking apart, this really is old news, US bases have planes on hard standings so you can see what type of base they are, (Nuke Bomber, fighter/interceptor, freight/refuelling, helicoper etc) and our bases are not much better - we just don't have the planes to look at.
@Frank - concrete sets as a result of a chemical reaction called hydrationgenerating heat and so should be able to set underwater, if not, simply build a cofferdam, pump out the water, build your underwater edifice, let the water back in and remove the cofferdam