It is a tradition, that a boat trip from Middelfart Gl. Havn is arranged every year in connection with Nature Day in Middelfart Municipality. During the trip, one or two guides will talk about nature in connection with Lillebælt, such as water level, salt concentration, historic information regarding the creation of Lillebælt during the Ice Age, or other subjects regarding nature.
During the voyage we will be looking for porpoises, which are one of the characteristic features of Middelfart and Lillebælt. The porpoise is one of the smallest whales in the world, and is found in large numbers in Lillebælt. Historically speaking, porpoise hunting was the one profession, which provided the daily living for many of the citizens of Middelfart. The lard of the porpoises was used for lamp oil.