*Larger screen ...
*800kHz SI frequency capability ...
*Newer version processor ...
*Navionics Platinum capability ...
*Sonar sharing possibilities with other units is more varied with the 999 ...
If your 798 is not the "HD" ... You don't have Ethernet capability ... The 999 does ...
If your 798 is the "HD" ... You get the same Ethernet capability as the 999 ...
Rickie