In sonar the higher the frequency the shorter the pulse length and also the finer the detail.
But because of the shorter length at 200 kHz you also do not have enough energy available to have great depth penetration.
That is why at 200 kHz you have narrow cone widths...a narrow cone at the higher frequencies allows good to moderate depth penetration while still getting excellent detail.
Most 200 kHz units can get 500' to 700' depths.
The lower frequencies have a much longer pulse lengths and thus have far more energy available for greater depth penetration.
But being a longer pulse length also limits the sensitivity to smaller targets but allows wider cone angles because of the the greater energy in the longe pulses.
Many 50 kHZ units can penetrate down to 2500' .
Most sonars have the capability of showing dual screen viewing...both 200 and 50 kHz.
That way the uses can compare the two returns and thus getter a greater amount of information on the same screen.