The Pentax Marines are not as good as the Fujinon stuff or the E series and later Nikon porros. They are better than the Nikon A series and prior. And generally better than the older Fuji stuff. About on par with the older classic style B&L Porros...though I favor the B&L porros....even the Japanese made Zephyrs and Discoveries over the Pentax Marine.
Pentax Marines are very good binoculars.