Info from HT; just realize there are lot's of deep water (1500 ft +) fishers on there:
https://www.thehulltruth.com/marine-electronics-forum/577088-airmar-b175m-vs-b175w.html
The high CHIRP should be good to 300' at least. The HW is very popular in Alaska was they mooch shallow & can see their baits.
You could always just add cash & get dual frequency CHIRP; just don't tell the wife/SO.
This is good information from ericl, and I will add some real BC experience.
I have a dual frequency Airmar TM275LHW, which besides the mounting differences I think would be very similar to the B175HW when I am using the high channel.
So far I have only fished the East side of the Island with this transducer, so I do not know it's full capability's yet.
I bought the dual frequency to use the low side to track bottom in deep water when running, turns out I don't need it.
I run the high side only, and I can see bottom in 900 ft of water at 25 knots (bottom, not fish). I've run the low side but never see anything of use, so I prefer not to split my screen.
Fishing halibut I can see my spreader bar while jigging at 250+ feet, when there's no drift (again on high chirp).
Of course it is excellent in the shallower depths that the salmon run at.
I think for most BC fishing applications that B175HW would be an excellent Transducer, and probably all you need.