Why dive fingerless gloves? Several reasons.
Perhaps you require extra dexterity to follow a line in zero / low viz conditions. Or may be you are diving where you are not allowed to touch things, ie coral, but you do want protection on your palm for coming up a line. Alternatively you need to easily grasp rocks to pull and glide through a cave, but you don't want to end up with sore paws resembling raw steak.
As far as I am aware, until now, it was very much 'do it yourself' if you wanted fingerless gloves. And depending on just how adapt you were with needle and thread, and perhaps a tactical application of Aquasure, you'd end up with a practical pair of fingerless gloves. Or something that would fray and split after a few dives. Now Mares has changed that with the launch of their Amara Gloves at DEMA.2015.
These double-lined 2mm neoprene gloves benefit from a trimmed thumb and first two fingers on each hand (index and middle finger). They will be available in six sizes from XX small through to extra large.