What Is a Marine Navigation Kit and What Does It Include?

Even on a vessel equipped with ECDIS, GPS, and AIS, there are situations where the only thing standing between a safe fix and a lost position is a pencil, a pair of dividers, and a paper chart. A marine navigation kit bundles the hand tools a mariner needs to plot a course, measure a distance, and fix a position without electricity.

Whether preparing for a licensing exam or maintaining backup navigation capability aboard a commercial vessel, the kit is the starting point. Here is what a standard navigation kit contains, what each tool does, and why the collection still matters.

What Is a Marine Navigation Kit?

A marine navigation kit is a set of hand instruments used to plot courses, measure distances, and determine bearings on a paper nautical chart. Kits are commonly used by deck cadets, licensing exam candidates, yacht skippers, and professional navigators maintaining backup proficiency alongside electronic systems.

A quality kit typically comes in a protective pouch or case for organized storage at the chart table or in a sea bag. Leading manufacturers include Weems and Plath, whose kits have been standard aboard commercial and recreational vessels for decades.

What Does a Marine Navigation Kit Include?

The contents vary by manufacturer and intended use, but most professional-grade navigation kits include the following core instruments.

Parallel Rulers

Parallel rulers are two straight rulers connected by hinged arms that keep both rulers parallel as they are "walked" across the chart. The navigator uses parallel rulers to transfer a bearing from the compass rose to any point on the chart, or to draw a course line parallel to a desired heading. A standard size for chart work is 12 to 15 inches.

Dividers

Dividers are a two-pointed instrument used to measure distances on a chart. The navigator sets the points to span a distance on the chart, then transfers that span to the latitude scale on the chart's margin, where one minute of latitude equals one nautical mile. Dividers are also used to mark off a set distance along a course line.

Course Protractor or Plotter

A course protractor (sometimes called a Breton plotter or Portland plotter) combines a protractor with a straightedge, allowing the navigator to read a bearing directly without walking a line to the compass rose. Plotters are popular because they work faster than parallel rulers on a moving vessel, where holding rulers steady against the chart can be difficult.

Pencils and Eraser

Chart work is done in pencil so corrections and old course lines can be removed cleanly. Navigation pencils are typically soft-grade (2B or similar) to mark clearly without digging into the chart surface. A good eraser removes marks without tearing or smearing the printed chart.

Magnifying Glass

A magnifying glass helps read small print on charts, including depth figures, light characteristics, and chart symbols that become difficult to distinguish in subdued bridge lighting or on densely printed charts.

Chart Correction Template

Some kits include a chart correction template or stencil for applying standardized Notices to Mariners corrections neatly and consistently.

Why a Navigation Kit Still Matters

Electronic navigation is primary on most commercial vessels, but SOLAS and flag state regulations require vessels to carry the means for backup navigation. Paper charts and the hand tools to use them fulfill that requirement. Even on a recreational vessel, a GPS failure far from shore turns a navigation kit from a backup into the only tool available.

Beyond regulatory compliance, manual chart work builds and maintains the foundational skills that make an officer a better electronic navigator. Plotting a fix by hand forces the navigator to think about position, bearing, and distance in a way that watching a screen does not. Maritime training institutions and licensing exam programs require candidates to demonstrate proficiency with manual plotting tools for exactly this reason.

How to Choose a Navigation Kit

Choosing the right kit depends on the intended use.

For cadets and exam candidates, a basic kit with parallel rulers, dividers, pencils, an eraser, and a sharpener covers the essential requirements. Professional navigators may want a more complete set that adds a course protractor, a magnifying glass, and a chart correction template. For offshore sailing, durability matters: brass or stainless dividers and well-built rulers withstand the humidity and knocks of life at sea better than plastic alternatives.

ANS carries navigation kits, individual dividers, and parallel rulers from Weems and Plath and other trusted manufacturers.

The Tools Behind Every Good Fix

A marine navigation kit is one of the least expensive and most essential pieces of equipment aboard any vessel. Six or seven simple instruments, combined with a corrected chart and a trained hand, provide a navigation capability that needs no power, no signal, and no software update. For navigation kits, nautical charts, and bridge instruments, contact American Nautical Services at +1 (954) 522-3321 or sales@amnautical.com.

Frequently Asked Questions

Q. What is included in a marine navigation kit?

A standard navigation kit includes parallel rulers, dividers, a course protractor or plotter, navigation pencils, an eraser, a sharpener, and often a magnifying glass. Professional kits may also include a chart correction template and a storage pouch.

Q. What are parallel rulers used for in navigation?

Parallel rulers transfer a bearing or course line from the compass rose to any point on the chart while keeping the line parallel. The navigator "walks" the connected rulers across the chart surface.

Q. What are dividers used for on a nautical chart?

Dividers measure distances by setting the points to span a distance on the chart, then transferring that span to the latitude scale, where one minute of latitude equals one nautical mile.

Q. Do I need a navigation kit if I have GPS?

Yes. GPS and electronic systems can fail, and SOLAS and flag state regulations require backup navigation capability. A navigation kit provides the tools to plot a course and fix a position on a paper chart without any electronic equipment.

Q. What should I look for when buying a navigation kit?

Look for quality construction (brass or stainless dividers, durable rulers), a protective case for storage, and instruments sized for the charts you will use. A 12-to-15-inch parallel ruler is standard for most chart work.

Q. Are navigation kits required for maritime exams?

Yes. Most maritime licensing and certification exams require candidates to demonstrate proficiency with manual plotting tools, including parallel rulers, dividers, and course protractors. A navigation kit is typically required equipment for the exam.