When you're shopping for marine electronics sonar navigation, the first question is not just which screen to install. It's whether you want a complete system or a repair project. These two chartplotters sit at opposite ends of that spectrum: a used Simrad NSS12 MFD with radar and Active Imaging Sonar, and a damaged Garmin GPSMAP 740s sold for parts or not working.
Quick verdict
If you want one large display that can serve as the center of your nav station, the Simrad NSS12 is the unit that delivers. If you want a much cheaper entry into Garmin chartplotting and you're comfortable with a project unit, the Garmin GPSMAP 740s is the one to consider. The Simrad NSS12 is listed at $1,199.95; the Garmin GPSMAP 740s is listed at $150.00. The right call comes down to how much work you are willing to take on after purchase.
Side-by-side comparison
| Product | Right for | Condition | Listed price |
| Simrad NSS12 MFD | Full-featured navigation hub | Used | USD 1,199.95 |
| Garmin GPSMAP 740s Chartplotter | Project chartplotter | For parts or not working | USD 150.00 |
Where each one wins
The Simrad wins when you want a complete navigation hub and you like the convenience of one-touch keypad shortcuts. It is aimed at boats where the helm needs to stay organized. The Garmin wins for repair-minded buyers who want a parts unit that they can bring back to life, not a ready-to-run head unit.
Product notes
Simrad NSS12 Boat Marine 12" Touchscreen FishFinder Radar GPS MFD Chartplotter
The NSS12 is the unit to grab when you need everything to work together. Its touchscreen uses simple menus and icons, and the keypad gives you one-touch buttons for important functions. That combination matters when you are in rough water and don't want to dig through menus. It combines GPS chartplotting, radar, and Active Imaging Sonar in one display, with enhanced inland and coastal charts that cover both river and offshore trips. If you switch between rivers and open water, having one screen that covers both is a genuine advantage. Choose it if you want one screen at the helm instead of separate instruments. The tradeoff is the used condition and the scope of capability. If you only need a simple chartplotter or a backup display, this is more navigation than you need.
Garmin GPSMAP 740s Chartplotter Marine GPS TESTED W/ Sun Cover Power Cable Cut
This Garmin is a parts-or-not-working unit, so know what you are getting. It comes with a sun cover and a power cable that has been cut, and the screen has sun damage. The unit turns on and functions, which is why it can still be a useful donor unit or repair project. The included cover is a small bonus, but you will need to address the damaged screen and replace the cable before it is usable. With no warranty, this suits someone who likes hands-on projects and doesn't need a plug-and-play install. This is not the choice if you need a display you can trust this weekend.
Final choice by use case
For a sportfishing center console or powerboat where multiple instruments need to come together on one display, choose the Simrad NSS12. For a hands-on project, the Garmin GPSMAP 740s is the pick.
