GPS and Chartplotter Buying Guide

What a Chartplotter Does

A marine chartplotter combines GPS positioning with electronic charts, showing your boat's position relative to coastlines, depth contours, navigation markers and hazards on screen. This provides a significant convenience and situational awareness benefit over paper charts alone, though navigation equipment should be used alongside appropriate boating judgement and local guidance rather than as a sole means of navigation. Most modern units also support waypoints, routes, tracking and integration with other onboard systems like sounders, radar and autopilots.

Standalone Units vs Combo Units

Standalone chartplotters are dedicated to GPS and chart display, generally offering a simpler, more affordable entry point. Combo units integrate chartplotter functionality with a fishfinder/sounder in one display, which is popular among Australian recreational fishers who want both functions without running two separate screens. Combo units generally offer good value if you want both capabilities, though a dedicated standalone unit paired with a separate sounder can offer more flexibility if you want to upgrade or replace one function independently of the other in future.

Screen Size Considerations

Screen size affects both readability and cost, and the right size depends on your boat, helm layout and how you use the unit. Smaller screens (around 4-7 inches) suit compact helm spaces and tighter budgets, and are common on smaller trailerable boats. Larger screens (9 inches and above) offer more detail and easier multi-panel viewing — useful if you're running split screens showing chart, sounder and other data simultaneously — but require more helm space and typically cost more. Consider your available mounting space and how much information you want visible at once before choosing screen size.

Chart Data and Coverage

Chart data quality and coverage varies between chart providers and regions, and it's worth checking that your chosen unit supports detailed charts for the specific areas you boat in, including any local knowledge overlays or specialised fishing chart data if that's relevant to your use. Some units come preloaded with base charts and allow additional detailed charts to be purchased or downloaded separately; check what's included versus what requires an additional purchase before comparing prices between models.

Touchscreen vs Button Controls

Touchscreen units generally offer a more intuitive, smartphone-like interface for zooming, panning and menu navigation, but can be harder to operate reliably with wet hands, gloves, or in rough conditions where a steady touch is difficult. Button and keypad controls can be more reliable in challenging conditions and don't require removing gloves, though the interface may feel less immediate for some users. Many higher-end units now offer both touchscreen and physical button control, combining the benefits of each.

Networking and Multifunction Displays

If you're building out a broader electronics system — combining chartplotter, radar, sounder and autopilot — checking that your chosen units are compatible with a common networking standard (such as NMEA 2000) allows data to be shared between devices and displayed together. This is particularly relevant if you're planning to add capability over time, since starting with networking-compatible equipment avoids the need to replace existing units later when expanding your system. Browse marine radar and marine autopilots at Marine Depot if you're planning an integrated system.

GPS Accuracy and Positioning Systems

Most modern marine GPS units offer good positional accuracy for recreational navigation purposes, with many supporting multiple satellite positioning systems (such as GPS and GLONASS together) for improved accuracy and faster position fixes, particularly in areas with partial satellite obstruction. Check the specific positioning systems supported by a unit if this is an important factor for your intended use.

Mounting and Power Considerations

Consider mounting location carefully for both visibility from the helm and protection from direct sun glare, which can make screens harder to read in bright conditions. Check the unit's power requirements against your boat's electrical system, and if you're networking multiple devices, plan cabling runs and connections as part of your overall installation rather than as an afterthought.

Backup Navigation Practices

Electronic navigation equipment is a valuable tool, but it should complement rather than replace fundamental navigation skills, paper charts as a backup, and general boating judgement, particularly for offshore or unfamiliar waters. Equipment can fail, lose power or lose satellite signal, so maintaining awareness of your position through other means — and carrying appropriate backup navigation gear — is sound practice regardless of how capable your chartplotter is. See our Compass and Navigation Gear Guide for more on backup navigation equipment.

Software Updates and Ongoing Support

Marine electronics manufacturers periodically release software and chart data updates, which can add features, fix bugs, or update navigational data as marks, hazards and regulations change. Checking how a manufacturer handles updates — whether via a computer connection, direct Wi-Fi update, or memory card — and whether updates are free or subscription-based, is worth factoring into your comparison, since a unit with poor long-term update support can become less useful over time even if the hardware itself remains functional.

Budget Tiers and What Changes Between Them

Entry-level chartplotters generally cover core GPS and charting functionality reliably, while mid-range and higher-tier units add features like larger and higher-resolution screens, additional networking capability, more advanced chart options, and integration with a wider range of sensors and other electronics. Rather than assuming a higher price always means a meaningfully better experience for your specific use, it's worth identifying which features actually matter for your boating pattern and comparing units at the price point that includes those specific features.

Trialling a Unit Before Committing

Where possible, viewing a chartplotter in person — checking screen brightness in daylight conditions, testing menu navigation, and getting a feel for touchscreen or button responsiveness — can reveal practical differences that specifications alone don't fully convey. If an in-person trial isn't practical, reading detailed user reviews and comparison content focused on real-world use, rather than manufacturer marketing material alone, can help fill in some of these practical gaps before you commit to a specific model.

Planning for Future Expansion

Even if you're starting with a simple standalone chartplotter, it's worth briefly considering whether you might want to add a sounder, radar or autopilot down the track, since this can influence which networking standards and expansion ports are worth prioritising now. A slightly higher upfront investment in a networking-capable unit can save the cost and hassle of a full system replacement later if your electronics needs grow.

Common Use Cases and What They Typically Need

A boater doing occasional weekend trips in familiar local waters generally has different chartplotter needs than someone doing regular offshore fishing trips or longer coastal passages. For familiar, local boating, a compact standalone or combo unit with base charts for your region is often entirely sufficient. For offshore fishing or longer passages, more detailed chart data, larger screen real estate for reading depth contours and structure, and networking capability to integrate radar or additional sensors become more genuinely useful. Being honest about which category best describes your typical boating helps avoid both under-equipping for genuine offshore needs and over-spending on capability you won't use for mostly sheltered, local trips.

Second-Hand and Older Units

If you're considering a second-hand chartplotter, either as a budget option or because it came with a used boat, it's worth checking whether the unit still receives chart data updates from the manufacturer, since older discontinued models sometimes lose ongoing support. A unit with no update path may still function for basic GPS positioning, but you'll be working from potentially outdated chart data, which is worth factoring into your decision, particularly for areas where markers, hazards or coastline features may have changed since the unit's charts were last updated.

Sunlight Readability and Screen Technology

Screen technology varies in how well it performs in bright, direct Australian sunlight, which is a genuinely important factor beyond raw resolution figures. Some display technologies are specifically designed for high outdoor brightness and remain readable even in harsh midday sun, while others can wash out and become difficult to read without polarised sunglasses or an awkward viewing angle. If possible, viewing a display outdoors in bright conditions before purchasing — rather than judging brightness from an indoor showroom or online listing — gives a much more realistic sense of everyday usability on the water.

Data Sharing Between Multiple Displays

On boats with more than one display at different helm stations — common on larger centre consoles or boats with a fishing station separate from the main helm — networked chartplotters can share waypoints, routes and sensor data between screens, so information entered at one station is available at the other. This is a genuinely convenient feature for boats with multiple crew working from different positions, though it adds another layer of networking compatibility to check when comparing units, since not all displays share data equally smoothly even within the same manufacturer's range.

Mistakes to Avoid

• Choosing screen size without considering available helm space and mounting position.
• Assuming preloaded base charts provide the same detail as purpose-bought detailed regional charts.
• Overlooking networking compatibility if you plan to expand your electronics system later.
• Relying solely on electronic navigation without backup charts or navigation skills.
• Mounting a unit where sun glare significantly affects screen readability.

Getting the Most From Your New Chartplotter

Once installed, spending some time familiarising yourself with your chartplotter's menus, waypoint marking and route planning in calm, low-pressure conditions pays off later when you actually need to use these features under more demanding circumstances. Marking key waypoints for your regular launch point, favourite fishing or anchoring spots, and any known local hazards early on turns the unit into a genuinely useful personal reference rather than just a generic chart display.

Weather Sealing and Ingress Protection

Because a chartplotter is typically mounted in an exposed helm position, checking the unit's ingress protection rating and the manufacturer's guidance on weather exposure is worth doing, particularly if your boat doesn't offer much shelter from spray and rain. Manufacturers publish specific ingress protection ratings for their products — check the specification sheet for your chosen unit and confirm it suits your boat's typical exposure rather than assuming all marine-branded electronics handle weather in the same way.

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Related guides: Marine Electronics & Navigation guides | Compass and Navigation Gear Guide | VHF Radio Buying Guide