When switching between 2D, DV, and SV, is there history displayed? In other words, if you happen to be in 2D sonar and go over a brushpile, if you switch to SV can you see the image in SV or does it just pick up when you switched? My old Garmin with the GVC-10 only displayed the new data, you couldn't scroll back, so you might only see half of the brushpile.