I recently took the plunge and started experimenting with semi-automatic fly reels while I was in Spain with my friend Pablo. The speed of line control they offer when moving from place to place or landing fish is incredibly efficient.
These semi-automatic fly reels from Baetis feature a machined aluminum body and a polycarbonate lever. They will quickly retrieve all your line with a flick or two of the lever. The drag tension is adjusted by a small included allen wrench which fits into a small hole on the face of the spool. I set the drag light and then add any extra tension with the palm on my free hand. The full cage on the reel prevents line slipping between the frame and spool. The FlyMatic has enough capacity for 4 to 6 weight lines but can accommodate smaller weight lines and Euro nymphing lines with added backing.
The reel weighs 165 grams/5.82 oz and will balance most Euro rods nicely into the cork.