They are a complete waste of money and only purchased by complete suckers - half the cost of them goes on duping people into thinking they are better than ones which sell for half as much, which are twice as good!
Yes, they are Marine/Leisure batteries. Starts my landie fine. Jump started my GT4 from them too (didn't need to start the landie to do so, despite me trying to jump start the GT4 from my wifes fiesta and failing miserably)
I paid £38 for my Disco battery three years ago, it's crancked, winched, lighted the way and heated 100's of brews and still going strong. As others have quite rightly said, Optima batteries are over priced W A N K