No, it doesn't see whales
We have Forward Scan and a Vulcan 7 in the cockpit
with Navionics charts
We have C-Map charts
in our Furuno Navnet
in the navstation networked to a display in the cockpit
, and Maxsea
TimeZero Professional on a laptop
at the navstation also running OpenCPN
with GE2KAP generated satellite
charts and a tablet in cockpit mirroring the laptop screen
...oh, and we have paper charts as well !
BUT the Forward scan is only any good if we are moving slowly and in calm water
. the boat
pitching slightly throws it all to hell, rolling not so much.
We go into unknown fairly shallow anchorages
with FS on, Navionics
Sonar charts on and an eye on the depth sounder
and eyes outside looking .
In some places we have found everything to correlate, in others not at all.
As for whales....seen a few, but never hit one.
Having said all that, 10 years ago we sailed around the reefs
with only paper charts and a hand held GPS
and never hit anything....