Saint Kitts and Nevis Coast Guard, since 1967?
St. Kitts has a designated “naval ensign”, but no navy per se. The coast guard flies it instead, and even then only on the two largest of its five vessels. So I guess that means there are only two of these flags flying in the world?
The design is on the model of the British white ensign: White field, red cross, and the national flag in the top left quadrant. This stretches the national flag out to a kind of ridiculous 4:9 ratio, which kind of messes up the star placement.