Your best bet is to watch the various lists such as the UDXF for when Naval exercises take place. Anytime you hear a broadcast using bigraphs or trigraphs (2 letter and 3 letter callsigns) you can safely assume you are hearing one of these. In fact, if memory serves there was a couple of such reports just recently.
As to which ones would make it to the East Coast (I think the last exercise was in the Pacific), you really need to understand how HF propagation works. Not at a scientist level, mind you - just enough to know the basics. You would know, for example, that a 11 mhz freq at 0300 might have a hard time making it due to a lack of daylight. There are, of course, other factors such as your own antenna...
Anyway our wiki has several links devoted to the topic. In fact the preamble for the page has a link to an article with much more information on the
HF article
73 Mike
