Chamberlain's do nothing policy and make-nice attitude led to the invasion of both Czechoslovakia and also Poland. Hitler was emboldened to invade both countries when Neville Chamberlain came back from a meeting with Hitler and declared there would be 'Peace in our Time". He naively believed Hitler was not interested in conquest in Europe. Following the invasion of Poland, both France and the UK finally saw the truth of Hitler and declared war on Germany.
Some navigation innovations included the astrolabe to determine latitude and the use of the compass to determine directions. A major development in the ships used was the triangular sail