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Round Island Passage Light Lighthouse

Fl R 4s🇺🇸Round Channel in the Straits of Mackinac, MI, USOperational

Location & Light Range

About Round Island Passage Light Lighthouse

This lighthouse stands 18 meters tall, with its light positioned 21 meters above the water. Constructed and first lit in 1947, it guides vessels through the Round Island Channel. The channel itself is a branch of Lake Huron, connecting important waterways. This structure is automated and unmanned, relying on modern technology for its operation.

Why it matters: The lighthouse is listed on the National Register of Historic Places.

Background
Round Island Passage Light is an automated, unmanned lighthouse located in the Round Island Channel in the Straits of Mackinac, Michigan. The channel is a branch of Lake Huron.

Light & Optic

Characteristic Signature
Fl R 4s
Flash Type
Flashing
Light Color
Red
Flash Count
1 flash
Interval
4s
Focal Height
21m
Light Range
14NM (25.9 km)

Construction & History

Year Built
1947
Heritage Status
National Register of Historic Places listed place

References & Identifiers

Wikipedia
Read on Wikipedia →
Wikidata
Q7371061 →
OpenStreetMap
View on OSM →

Tower & Structure

Tower Height
18m

Location

City
Round Channel in the Straits of Mackinac, MI
Country
🇺🇸US
Latitude
45.8429°
Longitude
-84.6152°

Nearby Vessels

Flag
Type
Name
Dist.
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Frequently Asked Questions

How far offshore can Round Island Passage Light Lighthouse be seen?+
With a focal height of 21 meters and a nominal range of 14 nautical miles (approximately 25.9 km), Round Island Passage Light is visible from well offshore under standard atmospheric conditions. Actual visibility depends on observer height, weather, and sea state. This range makes it a significant coastal navigation aid for vessels transiting the area.
How do mariners identify Round Island Passage Light Lighthouse at night?+
Round Island Passage Light displays the characteristic Fl R 4s — 1 red flash every 4 seconds. Each lighthouse has a unique flash pattern published in the List of Lights, allowing mariners to positively identify it and distinguish it from other navigation aids in the area. The red color may indicate a specific sector or warning zone.
Which ports and harbors does Round Island Passage Light Lighthouse guide vessels into?+
Round Island Passage Light Lighthouse assists vessels approaching 5 nearby ports. The closest is Mackinac Island at 0.1 NM to the NNE. Other ports served include MACKINAW CITY (5.9 NM SW), CHEBOYGAN (13 NM SSE), CEDARVILLE (14 NM NE), Brevort (20.3 NM WNW). Mariners should consult the relevant chart for full approach and pilotage information.
Is Round Island Passage Light Lighthouse still active and maintained?+
Yes, Round Island Passage Light Lighthouse is currently operational. It is actively maintained and continues to emit its characteristic light signal for marine navigation. Most modern lighthouses are automated and monitored remotely by the national maritime authority.
How can I track vessels near Round Island Passage Light Lighthouse?+
You can track vessels near Round Island Passage Light Lighthouse in real time using MarineRadar. The platform shows live AIS positions of ships in the area, including vessel name, type, flag, speed, and course. Use the "Track Vessels Nearby" button on this page to open the live map centered on this lighthouse.