I have never tested those transducers head-to-head. But if you just look at the specs your targets on the 50K side will be shorter using the R-99 due to the 9 degree width vs. 14 of the CA50BL-12HR. Targets should appear pretty much the same using either transducer on 200Khz.
Thank you Snips for your reply. As I can not find elaborate info on Furuno's transducers as much as I find on Airmar's , could you please based on you info advise which choice would be best in the 2kw range based on target discrimination and depth penetration.(bottom fishing upto 300m & offshore tuna fishing)
Target discrimination (resolution) has to do more with a sounders pulse length than beam width. Both transducers will work in 300m of water. I think it comes down to what you fish for the most. If it were me, I would chose the CA50BL-12HR for mid-water targets and the R-99 for fish on the bottom.