Why, when his sister and his nieces were visiting, would Uncle Henrik spend the whole night on his boat?

Uncle Henrik spent the night on his boat so that he could help the Rosen family and several other Jews escape from Denmark. Uncle Henrik left early to go to his boat while everyone else remained at his house. They pretended to mourn the loss of an aunt. This funeral was staged in order to explain why a large group of people (including the Jews who were trying to escape) had gathered at Uncle Henrik's house. After soldiers came to investigate the gathering, Peter and Mama led the group to the water in order to board Uncle Henrik's fishing boat. He planned to lead them to freedom in Sweden across the water. When they dropped an important package by mistake, Annemarie ran down to the water to give it to Uncle Henrik. Then he left with the small group on the boat to Sweden.