Best you read this document first.

Select what you want; I would avoid just using united states as your only criteria because you be trying (and system too) to load about 900 pictures. Only one selection from a given category but enter as many criteria as you wish.

Best to not use phone or tablet; you can try it but results aren't known.
You can rollover the pic to get the name (if there is one). You can click on a picture to view larger one . If you do, close the window to get back to the smaller pic.
There are videos too which surprisingly play when clicked; I guess it depends on whether one has a default video player.
The submit button is at the very bottom; when clicked you will get a display of pics meeting the criteria you selected.
To get back to the criteria selection page, click on the link at the very top of the picture display page.
FYI- We have been to every location in Loc_2} except Susan has not been to the Coast Guard related ones.