Watch a published character

Each of these five lights is still a working aid. The figures and the character strings come from Trinity House or the Commissioners of Irish Lights, retrieved on 15 November 2026. The published character is Fl (2) 10s, and the published range of the light is 17 nautical miles.⁠¹ The published character is Fl (2) 15s, the published range is 20 nautical miles, and the published intensity is 60,000 candela.⁠² The published character is Fl (2) WR 10s — a group of two flashes every ten seconds, white or red according to the sector. The published range is 15 nautical miles, and the published intensity is 14,400 candela.⁠³

The Commissioners of Irish Lights publish Fastnet’s character as Fl W 5s, the range as 18 nautical miles, the height of the tower as 54 metres, and the height of the light above mean high water springs as 54 metres.⁠⁴ Irish Lights publishes Hook Head’s character as Fl W 3s, also exhibited by day in poor visibility, with a range of 23 nautical miles, a tower height of 35 metres, and a height of light above mean high water springs of 46 metres.⁠⁵

Watch a published character

Pick one of five working lights. The lantern follows that station’s published grouping and period. A static description of the same character stays on the page. There is no timer and no score.

Station

Fl (2) 10s

A group of two white flashes, repeating every 10 seconds.

Trinity House publishes this character.

The flash length in the animation is illustrative. The authorities publish the grouping, the colour and the period; they do not, on the pages cited here, give a measured duration for each flash. If you have asked your device to reduce motion, the lantern stays lit and the pattern is described in words only.

How to read the abbreviations used on this site

These are the strings Trinity House and Irish Lights actually print for the five lights below, written out in plain English. This is not a complete glossary of every IALA abbreviation.

Published string	What it means on this site	Example
Fl W 5s	A single white flash, repeating every 5 seconds.	Fastnet
Fl W 3s	A single white flash, repeating every 3 seconds.	Hook Head
Fl (2) 10s	A group of two flashes, repeating every 10 seconds.	Eddystone
Fl (2) 15s	A group of two flashes, repeating every 15 seconds.	Bishop Rock
Fl (2) WR 10s	A group of two flashes every 10 seconds, white or red according to the sector.	Longships

Longships is the one station on the list whose published character is not only white. The WR in Fl (2) WR 10s is a sector: from one bearing the flashes are white, from another they are red. The simulator lets you switch sector. It does not invent bearings that the Trinity House page does not give.