The KNM Uller is a historical wreck located in Gulen, Norway, at a depth of 185 feet. This Norwegian Vale-class gunboat was built in 1876 and later converted to a minelayer. It was sunk during World War II after being bombed by the Royal Norwegian Navy. Scuba divers can explore this site but must be cautious due to its proximity to a major ferry route and the presence of unexploded mines. Navigation to the wreck can be tricky, so divers should prepare to use a surface marker buoy when surfacing.