The sonar works fine, and I bought a Magellan combination road/marine unit with the North lakes software, so I really do not need the GPS however my problem is how do I disable the GPS module so I do not get all the warning messages and alarms? I contacted Lowrance about 5 or 6 years ago inquiring about an upgrade, and the response was "sure, we have one, 650.00"...I said "I can buy a new one for that" and the response was...That IS our upgrade. I live about 200 mi. from Superior, and if I can get up there 4 times a season I feel lucky. To try to get $650.00 out of the wifes grocery money for something that is used 4 or 5 times a year? So much for that! Do the LGC-1 Antenna modules go bad? Thanks bser64