Force26,
The Tap settings are mainly based on the impendence of the transducers elements. For the R111LH you are using the correct settings, "B" for the LF side and "C" the HF side.
Even though you are using a 2Kw transducer you are in reality are only getting a fraction of that power being returned to the transducer, remember you are losing both sending and receiving.
Below is a comparison that I have posted a couple times before illustrating the performance loss that can happen when using in-hull transducers. The 2Kw 28Khz should have easily outperformed the 1Kw 50Khz, but as you can see it was no contest.
I wish I had some magic settings I could give you but I don't, sorry.
Snips