Compared to Series 10, Ultra 2’s durability has been improved. The sapphire display crystal is enhanced by a titanium case that has been modified to incorporate a raised edge around it. Also, the water-resistance has changed from the previous 50 meters for Series 10, to an impressive 100 meters for Ultra 2, which also has specialized diving features built into it. If I am going for things which will require better durability, then Ultra 2 is the option to go with.