Hello,
Since recently guide explaining how to convert you HB device to international has been published. This was headache for many fishermen outside US after saving some $ and buying it on Amazon/Ebay to switch to metric system and change language. This also allowed some companies to provide gray "solution" installing hacked firmware for clients and making money this way. Whatever commercial reasons HB had in mind back in days they decided to have domestic and international version, they didn't implement the protection on hardware, but on software level. This never was a big deal for people, who can reverse engineer the software, now everyone can ci->cxi conversion.
As I see HB is loosing it's competition to Lowrance in sonar market (personal opinion), that also can be caused by this versioning, there is no need to keep this trick in secret.
The detailed walkthrough is available using the direct
link to Medium.
Merry Xmas!