This picture is very puzzling. What is a storm badge pinned to a sailor cap?? To answer this question, every small detail of the picture would have to be examined. To what extent do the tunic and cap correspond to the dress code during the Great War? Unfortunately, I have very few photos from the Navy. In all of these, the sailors are wearing sailor’s blouses and bright clothing typical of the navy. Of course, in winter conditions, they could have worn a warmer jacket or cloak, but they also look more like a kind of overall and not the kind of tunic that we see in the photo. The cap looks like a seaman’s cap because of the ribbon, but also in its cut and shape. On the ribbon we read the name of the warship SMS Erzherzog Karl. This ship entered service in 1906 and was not among the most modern units during the Great War. She was the flagship of the 2nd Division stationed at Cattaro. It later left Cattaro naval base. At the end of the war it was seized by the French.
Instead of the insignia decorated with the monarch’s monogram on the sailor’s cap, he wears a small assault troop insignia typical of infantry. At first it looks like he might be some kind of marine, that’s why he has a mix of navy and infantry clothing, and that’s how he got the insignia. There was a marine coast guard unit in Pola, maybe he was one of its members? Determining this requires further research.