Hi,
Lake Lavon is not available on Navionics HotMaps Handheld. For a complete listing of lakes available on Navionics HotMaps Handheld please visit Navionics website at
www.navionics.comFrom Navionics homepage select LAKES, and then select North America. This will bring you to the lakes offering page. You will see what appears to be file tabs and the end you will see more with an arrow, select the more which will bring you to the complete lake listing for the HotMaps Handheld product.
The 2009 Navionics HotMaps Premium rebate program
2009 Navionics HotMaps Premium Lake Maps for Serious Fishing Now only $99 after MFR Mail-in Rebate. SAVE $50!! Purchase a new 2009 Navionics HotMaps Premium Chart at $149* from October 1 through December 31, 2009, and receive $50 cash back from Navionics! See HotMaps Premium Rebate Form for complete details @
www.navionics.com/HMPREM_rebate09form.pdfFor a complete lake listing select the 2009 Navionics HotMaps Premium and then select the region of interest.
In researching this for you I have found that Lavon in Collin TX is available as a Navionics Exclusive HD Lake Map (High-Definition Survey) on the 2009 Navionics HotMaps Premium South which is compatible with your IFinder unit.