Semium Lighthouse

Fl W 5s🇮🇩Riau Islands, IDOperational

Location & Light Range

About Semium Lighthouse

This white steel tower stands at a focal height of 160 meters. Its light displays a single white flash every 5 seconds. The lighthouse offers a geographic range of 22 nautical miles. It is located in the Riau Islands.

Light & Optic

Characteristic Signature
Fl W 5s
Flash Type
Flashing
Light Color
White
Flash Count
1 flash
Interval
5s
Raw Code
Fl.W. period 5s
Focal Height
160m
Geographic Range
22NM

Location

City
Riau Islands
Country
🇮🇩ID
Latitude
4.5153°
Longitude
107.7271°

Nearby Vessels

Flag
Type
Name
Dist.

Tower & Structure

Tower Color
white
Material
steel

Structure: White tower. SIANTAN:

References & Identifiers

Admiralty No.
F1836.6
NGA No.
21114
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Frequently Asked Questions

How do mariners identify Semium Lighthouse at night?

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Semium displays the characteristic Fl W 5s — 1 white flash every 5 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.

Is Semium Lighthouse still active and maintained?

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Yes, Semium 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 Semium Lighthouse?

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You can track vessels near Semium 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.

What is the Semium lighthouse used for?

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It is a fixed navigational aid on the coast at Riau Islands, ID. Mariners identify it by its light characteristic — the pattern, colour and timing of its flashes — which is unique among the lights in its area, so a bearing on it fixes a vessel’s position without instruments.