How to do icy water

I prepared this small vignette a few years ago as a present for couple of good friends, who left the old continent to spend half a year in USA. It represents George Washington’s crossing of the Delaware River during the American Revolutionary War or War of Independence (1776), and is inspired in an amazing painting by Emanuel Leutze (1851). Note that there are some inaccuracies that I replicated here, such as the flag. This would have been the right flag. Furthermore, the boats in this painting are a little bit too crowded, but Designs & Edits released a perhaps more…