One Large Chartplotter or Two Smaller Networked Units?

Key Takeaways: If you’re weighing up a single big chartplotter against a pair of smaller networked units, the choice comes down to how you sail and what you value most. One large screen gives you glorious clarity and a clean helm, but two smaller displays offer redundancy, flexibility, and the freedom to keep radar, AIS, and charts visible at the same time. Shorthanded cruisers often lean towards dual units for situational awareness, while coastal sailors may prefer the simplicity and cost savings of one well‑placed display.

The Core Question
What a Single Large Display Does Well
Where a Dual Display Setup Shines
What the Sailing Community Often Overlooks
Power, Space, and Installation Considerations
Reliability and Failure Modes
How Different Cruising Styles Influence the Choice
Cost Analysis: Not Always as Straightforward as It Looks
Summing Up

The Core Question

Most sailors reach this crossroads when upgrading electronics or refitting an older boat. Modern multifunction displays are powerful, bright, and capable of running every navigation layer you can throw at them. The real question is whether you want all that capability on one big screen or spread across two smaller ones.

Both approaches work. Both have drawbacks. The right answer depends on how you use your boat, how often you sail shorthanded, and how much redundancy you want built into your navigation system.

What a Single Large Display Does Well

A single large chartplotter is wonderfully simple. You get:

A clear, uninterrupted view of the chart

Fewer cables, fewer holes, and fewer potential failure points

A clean helm layout

Lower overall power draw compared with two units

A single point of focus when navigating in tight spots

Large displays also shine when you’re zooming in and out frequently or overlaying radar and AIS on the chart. Everything is right there in front of you, without the need to glance between screens.

Where a Dual Display Setup Shines

Two smaller networked units give you options that a single screen simply can’t match:

One screen for the chart, the other for radar or AIS

Redundancy if one unit fails

The ability to keep a dedicated instrument page visible

More flexible mounting options at helm and nav station

Better situational awareness when sailing shorthanded

Many cruisers like having radar permanently displayed on one screen during night passages or poor visibility. Others prefer to keep AIS targets visible at all times without cluttering the main chart.

What the Sailing Community Often Overlooks

A few practical considerations rarely get mentioned in casual dockside conversations:

Screen Glare and Viewing Angles
Two smaller screens can be angled differently, which helps when the helm is offset or when the sun is low. A single large display may force you into a fixed viewing position.

Heat Management
Large displays generate more heat. In a tight helm pod, that can shorten component life. Two smaller units often run cooler.

Human Factors
When you’re tired, cold, or managing the boat alone, having radar or AIS always visible without toggling menus can make a real difference.

Power, Space, and Installation Considerations

Power consumption varies by brand and model, but two smaller units typically draw more than one large one. On a long passage, that matters.

Helm space is another constraint. A 12 or 16 inch display can dominate the pedestal on a mid‑sized cruiser. Two smaller units may fit more naturally around existing hardware.

Installation complexity also increases with dual units. More cables, more network components, and more waterproofing.

Reliability and Failure Modes

Redundancy is the strongest argument for dual displays. If one unit dies, the other keeps you going. With a single display, a failure leaves you relying on tablets, phones, or a laptop.

That said, networked systems share data sources. If the backbone or power feed fails, both units may go down. True redundancy requires separate power feeds and at least some duplicated sensors.

How Different Cruising Styles Influence the Choice

Coastal Sailors
A single large display is often enough. You’re rarely far from land, you’re not typically running radar all night, and simplicity has real appeal.

Offshore and Shorthanded Cruisers
Dual displays come into their own. The ability to keep radar, AIS, and charts visible without switching pages reduces workload and helps you stay ahead of the boat.

Liveaboards
Many liveaboards like a helm display paired with a second unit at the nav station. It’s a comfortable way to plan routes, check weather, or monitor AIS without standing in the cockpit.

Cost Analysis: Not Always as Straightforward as It Looks

It’s easy to assume that one large display is cheaper than two smaller ones, but that’s not always the case. Prices vary widely between brands and screen sizes.

Here’s a simple comparison framework:

Setup	Pros	Cons
One large display	Clarity, simplicity, lower power draw	No redundancy, limited layout flexibility
Two smaller displays	Redundancy, flexible layouts, dedicated radar or AIS	Higher cost, more power, more installation work

Need help deciding which chartplotter suits your boat and your budget?
Click here to see my recommended models and comparison table.

Summing Up

There’s no universal answer. If you value simplicity, clarity, and a tidy helm, a single large chartplotter is a solid choice. If you sail shorthanded, run radar often, or want redundancy built into your navigation system, two smaller networked units will serve you better. Think about how you actually sail, not how you imagine you might sail one day, and the right option becomes clear.

This article was written by Dick McClary, RYA Yachtmaster and author of the RYA publications 'Offshore Sailing' and 'Fishing Afloat', member of The Yachting Journalists Association (YJA), erstwhile member of the Ocean Cruising Club (OCC) and owner/administrator of 'Liveaboard Sailboats for Sale'.