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The Sisters Lighthouse

Fl White 4s🇺🇸USOperational

Location & Light Range

About The Sisters Lighthouse

A 17-meter square skeletal steel tower stands on an island in Icy Strait. This structure carries an aerobeacon and emits a white flash every four seconds. The island is located in the center of Icy Strait, a 40-mile passage connecting the Lynn Canal to the Pacific Ocean near Cape Spencer. The site is open to the public, but the tower itself remains closed. The nearest port is Hoonah, 7.2 kilometers away.

Why it matters: This light is critical for safe passage through Icy Strait, a key waterway for vessels navigating between the Lynn Canal and the Pacific Ocean. Its unique design as a square skeletal tower carrying an FAA aerobeacon serves both maritime and aviation needs.

Light & Optic

Characteristic Signature
Fl White 4s
Flash Type
Flashing
Light Color
White
Interval
4s
Raw Code
Fl W 4s
Focal Height
21m
Geographic Range
13.4NM

Location

Country
🇺🇸United States
Region
Alaska
Sea Region
An island in the center of Icy Strait, a 40-mile passage connecting the Lynn Canal to the Pacific Ocean at Cape Spencer.
Latitude
58.1712°
Longitude
-135.2588°

References & Identifiers

Nearest Port
Hoonah(7.2 km)
Admiralty No.
G6479
USCG No.
6-24135

Tower & Structure

Tower Height
17m
Tower Shape
skeletal
Material
steel

Structure: A 17m square skeletal steel tower carrying an aerobeacon.

Visiting

Open to public
Site open, tower closed

Nearby Vessels

Flag
Type
Name
Dist.
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Frequently Asked Questions

How do mariners identify The Sisters Lighthouse at night?+
The Sisters displays the characteristic Fl White 4s. 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 white color may indicate a specific sector or warning zone.
Which ports and harbors does The Sisters Lighthouse guide vessels into?+
The Sisters Lighthouse assists vessels approaching 5 nearby ports. The closest is HOONAH at 7 NM to the WSW. Other ports served include Excursion Inlet (15.8 NM NNW), Pleasant Island (16 NM NW), Hawk Inlet (16 NM E), Gustavus (19.7 NM NW). Mariners should consult the relevant chart for full approach and pilotage information.
Is The Sisters Lighthouse still active and maintained?+
Yes, The Sisters 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 The Sisters Lighthouse?+
You can track vessels near The Sisters 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.