Your picture reminds me of my childhood - living in Vaasa - west coast of Finland - the narrowest spot in Bothnic Bay between Finland and Sweden - there was enough boats then to evacuate the whole population at same time, if needed. My mother - who had lived the war used to say "When the russians attack, then . . ." - instead of "If the russians attack, then . . . " My father who had spent his youth at front and got shot thru his kneecap never said something like that, though. He was in artillery and in charge of over 100 cannons. All he ever spoke about it was that it was horrible no-good time for all - he did not hate the russians. Even though he saw many of his mates die.
He wrote a diary, that was published - I've heard rumours that it has been translated and used in other countries for training - but I'm not sure.
Reason I started w your picture reminding me . . . My US relatives told me they had these excercises at school - they had to duck under their desks etc - we never had such.