Using graphic elements like this world map, to see in which countries or regions of the world the surname Trowler is more common, is of great help.
The quantity of people with the surname Trowler that we can find in each country can help us discern the origin of the surname Trowler, as logic tells us that the place with the most people surnamed Trowler will be the country or area of origin of the surname Trowler.