Three of the improved Type 206 boats were later sold to the Israeli Navy, becoming the Gal-class. The German Type 209 diesel-electric submarine was the most popular export-sales submarine in the world from the late 1960s into the first years of the 21st century. With a larger 1,000–1,500 tonne displacement, the class was very customizable and has seen service with 14 navies with 51 examples being built as of 2006.