Marine Electronics Questions? Ask a Technician for Answers ASAP
Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
The Follow The Contour feature is appropriate for new uncharted bodies of water, and writes to the chip. It wouldn't work if
A. the chip's files are being protected from overwriting - which is sometimes the case, and
B. if the Humminbird device software is not of the right version, perhaps... what is the version on your 999hd si ?
C. if you are in an already-established chart. I suspect a blank chart area (at least) may be required.
Also, you might need this software: