HB GPS cannot accurately calculate position at less than 0.6mph so the Chart boat icon changes to a circle below that 0.6mph ...
The AS GPS HS antenna can help with slow speed operation because the AS GPS HS antenna also has a magnetic compass that can show boat “orientation” (boat icon instead of circle) on the Chart view even when stationary ...
https://humminbird.johnsonoutdoors.c...heading-sensor
Unfortunately the HELIX 7 is not a simple connection to the AS GPS HS antenna (but it can be done) ...
https://www.humminbird.com/support/faqs/HELIX_EXT_GPS
Rickie