10 Great Loop Navigation Mistakes First-Time Loopers Make

Navigating America’s Great Loop differs from following a track from a map. The route goes through coastal waterways, canals, rivers, and big lakes with various depths, bridges with restrictions, locks, currents, and weather changes. A miscalculation can place a boater in shallow water, create a clearance issue at the bridge, or require an unplanned deviation from the route.

Here are 10 navigation mistakes that a new Looper should be aware of.

1. Thinking the Great Loop Route Is Fixed

Although the Great Loop is about a 6,000-mile route, it is not a fixed route. According to AGLCA, it consists of several major segments and different routes, especially near New York, Canada, and other sections.

In fact, your air draft will be a factor when choosing a particular route to take, such as the Erie Canal, the Triangle Route, or the Oswego Canal route to Lake Ontario.

Plan each segment of the route separately and do not create one long track that would fit the whole journey.

2. Relying on One Navigation Source Alone

Chartplotters and other navigation apps are handy tools but shouldn’t be your sole source for information. Levels, bridges, locks, and local conditions can change.

AGLCA has current information about waterway and lock closures, whereas navigation charts give you the geographic information needed.

Prior to departure, match your chart against current notices, lock conditions, and weather.

3. Overlooking Your Boat’s Air Draft

This is one of the most important measurements to make on the Great Loop.

The current low fixed bridge on the Loop, according to AGLCA, is 19.6 feet on the Illinois River. The air draft on your boat goes beyond the height of the cabin roof and will include such things as radar arches, antennas, satellite communications gear, and Biminis.

There is additional route consideration in New York. AGLCA indicates that a boat with an air draft of 15 feet or less can go through the Erie Canal to its westward terminus on Lake Erie.

A minimum air draft of 17 feet permits passage on the Triangle route via Lake Champlain and the St. Lawrence Seaway, while the 21-foot bridge clearance on the Erie Canal-Oswego Canal route to Lake Ontario makes this route necessary

Take your measurements when your boat is set up for cruising before choosing the right route.

4. Mistaking Air Draft For Water Depth

These are two separate navigational limitations.

The air draft determines if you will fit under the bridge. Draft will determine how deep the water must be under your hull.

Confusion between the two can result in poor route choices. Your boat could fit underneath all the bridges on a planned route, but there would still be insufficient water under its keel.

Take both measurements and use the correct one when checking your charts and routes.

5. Planning Only By Distance

Not all 50 miles on a river are equal to 50 miles at sea.

There could be waiting for locks and their transits, bridges with specific opening hours, tidal currents that will slow you down, and commercial traffic affecting your progress on inland rivers.

Build your daily plan according to the cruising conditions, not just distance.

6. Ignoring Bridges and Lock Research

Information regarding bridges and locks is part of your navigation planning process; do not wait to find out about bridges and locks until arrival at the destination.

ICW routes have bridges that open at specific times; the New York canals and inland waterways have locks with specific times and methods of operation. Closing times of bridges can alter a navigation plan. This issue is illustrated by AGLCA closures.

Find bridges, locks, and restricted areas for each daily navigation leg. Be aware of bridges and locks with limited operating hours.

7. Relying on GPS and Neglecting the Chart

GPS will tell you where you are. It doesn’t automatically make it a safe route.

The GPS navigation system will show you the vessel’s position as it nears shallower water, restricted channels, bridges, and/or other changes in conditions. The captain must interpret the depth of water on the chart, aids to navigation, danger, and the vessel's draft.

Utilize GPS as one of your navigational tools, not as a replacement for navigational techniques.

8. Failure to Download Maps for Offline Use

Not all places in the Loop are covered by cellular services. Some inland rivers, waterways in Canada, and some coastal areas may experience poor cellular services.

Maps downloaded prior to arrival provide you with navigational details, even without an internet connection.

The GPS Nautical Charts' i-Boating software provides offline map downloads, route guidance, and other functions related to marine navigation. Download maps of those regions that you will need before disconnecting from the internet.

9. Overlooking the Conditions of Weather and Water

Even when a route is feasible, it does not mean it is the best route to choose for that day.

Wind is important in the Great Lakes and coastal waters. Levels of the rivers can influence depths and currents. Storms can also influence weather and water conditions rapidly. Planning trips in the Gulf Coast region also involves paying attention to hurricane conditions.

Weather and water forecasts should be checked before the trip and throughout the day. When conditions change, the itinerary should be adjusted.

10. Failing to Build Alternate Routes

There should be a Plan B for your Great Loop journey.

It may be closed for the bridge, locks, low water level, wind, or mechanical issues. Examples of waterway disruptions that affect the Loopers are provided in AGLCA’s present closure information.

Prior to every large section, find alternative routes and places for stopping. It is essential on big junctions like New York, Chicago, and the inland-river network.

How to Navigate the Great Loop More Successfully

Proper planning and frequent updates are key factors of successful loop navigation. Know the air draft and draft of your vessel. Consult charts prior to departure. Study bridge and lock information. Download charts for offline use. Watch the weather, water level, and closure information. Above all else, update your plan according to conditions.

GPS Nautical Charts’ i-Boating provides offline marine charts, automatic route creation, route assistance, off-route alerts, marine weather information, and tide/current data. Use these tools with current waterway information and sound seamanship.

Being able to plan flexibly is one of the benefits of undertaking the Great Loop. Consider whether or not the course fits your boat as well as the navigational restrictions for the day. This will help you avoid making errors that would otherwise be unnecessary.