Posts: 742
Location: Grand Rapids MN | The HD transducer has 455 and 800 kHz frequencies while the standard has just the 455. The higher frequency allows for more detail but both has it's place; otherwise the HD would just ditch the 455.
The upgrade is Humminbird will allow you to trade in your unopened standard transducer plus about $60 for the HD. If you open it then you can't trade. If I knew this when I bought my boat and had the dealer install a new 899 SI, I would have paid the extra for the HD. That transducer is couple hundred plus if one was to change their mind down the road. I wasn't pleased when I realized my HD graph didn't come with an HD transducer but I do like the unit. |
