I'll try and be as brief and concise as possible. I have a Garmin Striker Vivid 9sv. Great inexpensive unit except for one thing: it has no SD card for importing waypoints. I have a GPX file holding 1,500 waypoints on my lake but can't import them to my Garmin. I'm thinking I could purchase an older, used sonar unit w/sd slot to import my waypoints. Then, motor to the waypoints and use my sidevu, downvu, etc for actual target imaging. Problem is.. don't know anything about what units might work for this. Any suggestions?