No google, off the top of me noggin.
Ferox in Ennerdale, Wastwater, Windermere and Crummock and Thirlmere.
Used to fish Crummock a bit in my youth. Funnily enough we used to catch minnows by the boats to troll for trout, failing that we used spinners. Caught a few char on the spinners but no ferox. Not surprising really as Ron Greer states in his book that they only caught one ferox on small spinners; really need to use a lure that is bigger than 3 inches in his opinion.
Ask Mark Hirst how many ferox he has caught on intermediate line and size 8 and 10 traditional wet flies. You will be staggered by the response. He doesn't fish anything else for them.
Our best effort was 10 of us for a week on Lochy and Arkaig and Shiel (and I accept the Shiel fish are not ferox, but big browns), under Mark's guidance, caught 8 fish over 6 lb. Total weight of those eight fish was 80 lb, best at 16 lb 12 oz (from Lochy).
Matt Eastham and his mate went up for 3 days with Mark and fished traditional wet fly on Lochy and Arkaig and had one at 12 lb and one at 15 lb.
This is Matt with his fish...
The main diet of the ferox is char, but they are opportunists. We were on Arkaig one day and the trout were rising to a fall of coch-y-bonddu beetles. My boat partner caught a ferox of 11 lb 12 oz on a Silver Invicta. And it was coughing up coch-y-bonddus in the net...
Imagine hooking that on a size 16 dry fly!
Reading those papers on ferox, yes, they will dive to 30 m in pursuit of char, but they spend a lot of their time in water between 15 and 25 feet deep (which is the sort of depth Mark targets), and they hold station not that far down. The water being gin clear, they will come up and take a Kate muddler or Mark's favourite Stone Goat... if you are in the right place at the right time.