How to Choose a Marine Chartplotter (Garmin, Raymarine & More)

A chartplotter is the brain of your helm — GPS navigation, sonar, radar and engine data on one screen. With Garmin, Raymarine, Simrad and Lowrance all offering overlapping line-ups, here’s how to cut through the spec sheets and choose the right multifunction display (MFD) for your boat.

1. Screen size & resolution

Bigger screens are easier to read at a glance and split better into multiple panes (chart + sonar + radar). On a center console, 7″–9″ suits a single helm; 12″–16″ is ideal when you want full-screen sonar and charting side by side. Look for high-bright, IPS, sunlight-readable panels with a wide viewing angle.

2. Sonar / fishfinder type

This is where models really differ:

• CHIRP sonar — sweeps a range of frequencies for sharper target separation than traditional 2D sonar. The baseline you want today.
• DownVü / DownScan / ClearVü — photo-like image directly below the boat for structure.
• SideVü / SideScan — scans out to the sides; great for finding fish and structure over a wide area.
• Live sonar (Panoptix LiveScope, Active Imaging Live) — real-time moving sonar; the premium tier for serious anglers.

3. Charts & cartography

Check what’s preloaded (basemap vs detailed charts) and which cards it accepts — Navionics and C-MAP are the two big ecosystems, with features like high-res bathymetry, auto-routing and dock-to-dock guidance. Factor a chart card into your budget.

4. Networking & expandability

If you plan to add radar, autopilot, AIS, engine monitoring or extra displays, networking matters. NMEA 2000 ties sensors together; Ethernet shares radar and sonar between MFDs; NMEA 0183 handles legacy gear. Buy into a brand ecosystem you can grow with.

5. Touchscreen, GPS & the rest

Touchscreens are intuitive; keyed/hybrid units are easier in rough seas or with wet gloves. Confirm a fast multi-constellation GPS/GLONASS receiver, and check for built-in Wi‑Fi/Bluetooth for app control and chart updates.

Quick pick by boat

• Bay/center console: 7″–9″ CHIRP + DownVü/SideVü, Navionics or C-MAP.
• Offshore: 12″+ with radar & AIS over NMEA 2000/Ethernet.
• Serious angler: add live sonar (LiveScope / Active Imaging Live).

Shop & install

See our full range of chartplotters & MFDs and supporting marine electronics from Garmin, Raymarine and more. Want it wired and networked correctly the first time? Our Pompano Beach, FL shop does professional marine electronics installation — request a quote.