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Choosing a chartplotter by helm space, the brand you have, and what comes later

Pick the screen last. First measure the dash, count what's already on the network, and decide whether radar or live sonar is coming in the next few seasons.

GUIDE 03Reviewed November 2026About 11 min read

Three questions that decide most of it

  1. What physically fits at the helm? Width, height, depth behind the panel, and where the sun hits.
  2. What brand is already on the boat? Transducers, radar, trolling motor, and other displays decide more than the screen does.
  3. What’s coming later? Radar, live sonar, a second display, digital switching. Buy the screen that can grow into them.

Screen size and features only matter after those three are answered. If you haven’t done the inventory yet, start with the electrical-system guide.

Measure the helm, not the brochure

  • Flush-mount opening: measure the usable width and height of the flat panel area, not the whole console face. Curves, switch panels, and grab rails eat space.
  • Depth behind the dash: measure to the nearest obstruction, then leave room for cable connectors and bend radius.
  • Bracket mount: if you’re mounting on top of the console, check clearance to the windshield and T-top frame, and whether the unit blocks your sightline.
  • Viewing distance and sun: where you stand, where you sit, and whether the screen faces the afternoon sun on your usual heading home.

Get the exact cutout template from the manufacturer’s installation manual for the specific model before you cut. As an example of how much a model can differ from a “12-inch” assumption: Simrad lists the 12″ NSX ULTRAWIDE at 13.30″ wide, 5.82″ high, and 3.48″ deep without bracket. That’s a very different shape from a conventional 12″ display.

Ultrawide: one screen instead of two

Ultrawide displays are built for helms that are wide but short, which describes a lot of center consoles, pontoons, and wake boats. Two current options: Garmin’s GPSMAP 15x3 (15-inch ultrawide; suggested retail at its 2025 launch was $4,499.99) and Simrad’s NSX ULTRAWIDE in 12- and 15-inch sizes. If your dash can only fit one unit but you want chart and sonar side by side, they’re worth measuring for.

The brand you already have

This is the part retailer roundups skip. Each major brand has its own network for radar, shared sonar, and video. NMEA 2000 lets brands share basic data such as GPS, depth, engine data, AIS, and heading, but it won’t carry one brand’s radar picture to another brand’s screen.

If you already have…Staying in-brand usually means…Switching brands usually means…
Transducers on the hull or transomPlug in and go, if the new unit supports that transducer type and connectorNew transducer(s), sometimes new holes. Adapters exist for some combinations, with limits.
A radarReconnect it over the brand networkA new radar, or a second display just for radar
A networked trolling motorKeep route-following and spot-lock control from the plotter (for example, Garmin Force works with Garmin plotters)Lose plotter control of the motor
Charts and waypointsKeep your chart subscription and saved dataNew chart purchase; export waypoints as GPX, which most brands can import

None of that means you should never switch. It means the real price of switching includes the transducer, radar, and chart line items, not only the screen.

What the main lineups look like in 2026

From each maker’s current US product pages, checked November 2026. Sizes are display diagonals.

BrandSeriesSizesNotes
GarminECHOMAP UHD25, 6, 7, 9″Entry fishing combos; sv models include traditional CHIRP plus ClearVü/SideVü scanning
ECHOMAP Ultra 210, 12, 16″Higher-resolution screens, LiveScope compatible, wireless Force trolling-motor control, multi-band GPS
GPSMAP x37, 9, 12, 15″ ultrawide, 16″With or without built-in sonar; supports LiveScope, Panoptix, radar, and Garmin Marine Network
GPSMAP 900010–27″Flagship; sonar via separate module (xsv models 10–17″ have it built in)
SimradGO7, 9″Simple touchscreen units with built-in sonar and radar support
NSX7, 9, 12″All-in-one for cruisers and center consoles, NEON OS
NSX ULTRAWIDE12, 15″Ultrawide format; supports Halo and other Simrad radars; receives AIS over NMEA 2000
NSS 4—Premium touch-plus-keypad units with dual-channel CHIRP
NSO 416, 22, 24″Glass-helm modular system for larger boats
RaymarineAxiom 27, 9, 12″Chartplotter only or with built-in RealVision sonar
Axiom 2 Pro (S / RVM)9, 12, 16″HybridTouch (touch plus keypad), LightHouse 4; S = single-channel CHIRP, RVM = 1 kW CHIRP plus RealVision MAX
FurunoNavNet TZtouch312, 16, 19″Built-in dual-channel 1 kW TruEcho CHIRP; the 12″ adds a RotoKey and buttons
Simrad’s NSS 4 size range wasn’t listed on the overview page we checked, so it’s omitted rather than guessed.

Plan for radar and sonar now

The cheapest time to plan for radar or live sonar is before you buy the display. Check, for the exact model:

  • Network port: does it have the brand-network port the radar or sonar module needs, and how many?
  • Radar compatibility: which radar models it supports. For example, Simrad lists Halo dome, Halo open-array, 3G/4G, and HD radars for the NSX ULTRAWIDE.
  • Sonar: built-in channels versus a separate sonar module, and whether live sonar is supported and how it connects.
  • Power: radar and live-sonar modules add real current. Put them on the load list now.
  • Cable routes: a radar on a T-top means a cable path up the leg. Pull a messenger line while the console is open.

Putting it together

Your boatUsually the sensible move
Bay boat with a networked trolling motor and good transducersStay in that brand. Spend on screen size and sonar, not on a brand switch.
Center console, wide-but-short dash, radar plannedMeasure for ultrawide or two matching units; confirm radar support and network ports before buying.
Small cruiser, mostly navigation, older mixed-brand gearA good moment to pick one brand for display and radar, and use NMEA 2000 for everything else.
Any boat with weak batteries or undersized helm wiringFix the power first. A new screen won’t fix resets or noise.
Fit check: before you buy the screen
  • I have the cutout dimensions and depth from the installation manual and they fit my dash.
  • I know which of my transducers, radar, and motor will still work with it.
  • It has the network ports for what I plan to add in the next few seasons.
  • The new load list still fits my batteries and charging.
  • I’ve priced the whole change: screen, transducer, charts, cables, and mounting.
Before you pick up a crimper

This guide is for planning and for asking better questions. It is not an installation manual. Wiring, fusing, and battery work should follow ABYC standards and the equipment maker’s instructions; if you’re not sure, have a qualified marine electrician, ideally one who is ABYC-certified, design or check the work.

Product names here are examples, not endorsements, and nothing on this page is a paid placement. Some links may become affiliate links once those programs are set up; if they do, it will say so, and it won’t change what we suggest.

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