Regarding the recent post about toy divers: A friend of mine named Randy used to erect a toy train layout every year for Christmas and each year it had a different theme. In 2002 he built a Navy Layout (he was former Navy). One of the many interesting details was a small tank of water (aprrox 12"x12" x3") installed under the drawbridge in such a way as it appeared to be a part of the naval yard entrance. In this tank he would place several of those plastic toy skin diver's that I believe used baking soda to get them to rise and lower. I rememebr seeing these kinds of toys when I was a kid but they are still available and Randy used modern era versions of the toy for his set-up. The only two photos I have show the tank and the diver's but NOT the diver's in the tank :-(
More divers to come later from Andy B!