Maslen Cape is a boat-only Ropotamo reserve dive on Bulgaria's Black Sea coast, combining a sea entry, a narrow tunnel, and an upper cave-floor passage that rewards disciplined buoyancy. It is a compact, technical-feeling route best suited to advanced divers who want a short, memorable swim-through rather than a long exploratory wall. Expect a site that is popular, weather-sensitive, and more about precise entry control than easy shoreline convenience.