Older navionics chip compatibility guide

[beer batter]

Is there a Navionics table somewhere that lists 1-2 year old chips and their compatible GPS graphs?

I have a Humminbird 595c from 2008 (it was discontinued that year). The lakes I mainly fish were mapped out and added to the Navionics 1 foot contours in 2009. The Humminbird 595c manual says the HotMaps Premium chip is compatible, but that's from 2008. How to tell if the 2009/2010 Hotmaps Premium would also be compatible?

Also, what's the difference between the Premium and Platimum chips? The manual states that only the Premium chip is compatible with that GPS unit which is strange because I assumed the difference in chips was just more lakes.

[PerchJerker]

The compatability guide on the Nav site lists the 595 as being compatible with Hotmaps Premium cards. If you're not sure about the 2009 or 2010 Premium cards you should call or email Navionics to find out if a 2009 or 2010 card will work in your 595.

The Premium card has lake info. The Platinum card has info for the same lakes, but more info --- 3D views, Panoramic Views, satellite imagery, etc.