How to Use a Chartplotter Without Losing Your Navigation Skills

Electronic information is not the whole picture

GPS receivers, chartplotters and tablets can provide useful position data to recreational sailors. Captain Rick Robey's Integrated Navigation course asks whether watching a screen too closely can weaken a skipper's awareness of the real environment.

American Sailing presents the lesson as an argument for combining modern equipment with traditional seamanship. Technology should support an understanding of the water ahead rather than replace it.

Keep looking beyond the display

Other vessels, floating objects and changing weather may demand attention before a chartplotter raises an alarm. A proper lookout and direct observations remain essential even when electronic information appears accurate.

Skippers should compare what they see with charts and expected landmarks. A display showing a safe course cannot eliminate every collision or grounding risk.

Multiple systems may share one error

Position data can be transmitted from a common receiver to several displays, creating an illusion of independent confirmation. If that source is wrong, different screens may agree while the vessel is not where the crew believes it to be.

Knowing how equipment is connected helps crews respond when readings look suspicious. Paper charts or independently obtained information can be useful depending on the boat and circumstances.

Real accidents offer lessons

Robey draws on marine incidents, including a grounding involving the cargo ship Ever Forward, to illustrate failures of awareness and judgement. The point is not that electronic navigation is inherently unsafe, but that complacency can accompany sophisticated tools.

Recreational crews can learn by discussing potential errors before a trip. Identifying shallow areas, crossing traffic and alternatives in advance makes better use of the technology available.

Practice the human part of navigation

American Sailing's course encourages participants to develop an integrated approach using position, weather, rules and observations. A skipper should be able to explain the route and potential hazards rather than rely solely on a coloured line.

Regular practice of bearings and basic chart work builds confidence if an electronic system becomes unreliable. Good navigation combines instruments with judgement.

Understand where the displayed position comes from

A chartplotter usually receives satellite-derived location information through an internal receiver or a connected system. Several onboard displays can show the same coordinates, but that does not mean each has independently verified the position. A skipper should know which devices share the same receiver and what happens if its signal fails or becomes inaccurate.

Boat owners sometimes add tablets and phones as convenient navigation tools. These can be useful, but they may depend on the same satellite networks and may also lose power or suffer poor visibility in sunlight. Independent checks can include identifiable landmarks, depth information and radar or visual bearings where the equipment and conditions permit. The goal is corroboration, not an ever-larger collection of screens.

Read the chart rather than just following a line

An electronic route can guide the crew toward a destination, but it does not remove the need to examine the water along the way. Shallow areas, buoys, traffic separation schemes and local restrictions require attention at the planning stage. A line drawn across a map is not evidence that every part of it is safe for the vessel's draught and the conditions.

Electronic charts must also be kept appropriately updated, and their scale matters. A display may hide small details when zoomed out, while excessive zooming can create an impression of precision that the underlying survey does not support. Skippers should compare the route at useful scales and consult navigational warnings before getting underway.

Use eyes and ears as active navigation instruments

A lookout is a continuous responsibility that cannot be delegated to a chartplotter alarm. Floating timber, fishing buoys, swimmers and unlit small craft may be difficult or impossible for electronic systems to identify. The crew should regularly scan the water and maintain awareness of the vessel's actual surroundings while someone manages any onboard display.

Sound can also provide important clues in reduced visibility, including engine noise, fog signals and wave activity near shore. These clues require careful interpretation rather than guesswork. Radar and automatic identification information may help where fitted, but neither technology reports every vessel or obstruction. A prudent skipper uses complementary observations.

Prepare for degraded or missing GPS

A navigation failure is easier to manage when the crew has already practised other methods. Recording an approximate position, speed and course at sensible intervals can provide a starting point for dead reckoning. A suitable chart, compass and awareness of distance travelled help sailors judge their likely area even without a reliable satellite fix.

Such estimates become less certain as time passes, particularly in changing tidal streams and winds. Crews should acknowledge that uncertainty and avoid trying to force an exact answer from incomplete information. Choosing safe water, reducing speed where appropriate and seeking reliable assistance may be better decisions than continuing rapidly toward a waypoint whose position is now doubtful.

Organise an effective navigation routine

For longer trips, a simple routine can divide attention between steering, observing traffic, reviewing the route and checking weather. On a small boat, one person may need to cover several roles, making it especially important to avoid lengthy screen interaction at critical moments. The system should reduce workload rather than turn navigation into an exercise in operating menus.

After a voyage, note any chart discrepancies, unexpected shallows or equipment problems while the details are still clear. Check the cause before changing settings or updating a route for future use. Electronic navigation is most valuable when the skipper remains able to explain where the boat is, where it is going and what might make the planned course unsafe.

Tides and currents add another layer to the problem because a vessel can be pointing in one direction while moving across the seabed in another. A chartplotter may show course over ground, which is not identical to the compass heading. The skipper should understand that distinction before assuming the displayed track explains everything the yacht is doing.

Power reliability deserves similar attention. A chartplotter that is easy to use at the berth will not help if its supply is interrupted, the display becomes unreadable or water damages a connection. Checking the electrical system and knowing how to reach alternative navigational information should be part of the same ordinary equipment routine as checking engine and safety gear.