NAVIGATION BEACONS / RADIO-BEACONS
Sea-lanes are denoted by visual markers, lights, sound warnings and by electronic appliances. Visual markers by day and lights by night are most important for vessels.
In the Republic of Croatia the International IALA A-system for denoting of sea-lanes is being used: lateral combined with cardinal.
Beacons may be anchored buoys or stationary. Full details are given in Pilot 1 The Adriatic Sea (east coast) and in Pilot 2 The Adriatic Sea (west coast) and in the List of Lights in the Adriatic, Ionian Sea and Maltese Islands published by the State Hydrographic Institute in Split. Light signals are best studied for each case separately.
Beacons in the Lateral System. The beacons in this system denote the port (left) and starboard (right) sides of fairways and navigation channels, the port marks to be left to port, the starboard ones to starboard. Port and starboard are given according to the course that a vessel would sail into harbour, channel or river mouth from the open sea. In navigation channels that run parallel to the coast and can be approached from either end, port and starboard are denoted according to the route which would be taken when sailing north-west. If a navigation channel following the coast changes of direction port and starboard are given in the line of course following the hands of the clock. Stretches of river that are navigable for sea-going boats are given as if the vessel were sailing upstream.
In the international system starboard side markers are conical; they have a conical top mark and are coloured green. At night they show green lights.
Port side markers are cylindrical; the top mark is cylindrical and they are painted red. At night they show a red light.
If there are a number of the same markers along the lane which are difficult to distinguish then they must be signed by numbers or letters. The lights of such markers must differ from the light showing bifurcation of the channel.
Bifurcation of channel and marks denoting the main channel are shown by lateral markers which are coloured with red and green horizontal stripes. Cylindrical markers (red-green-red) with red cylindrical top mark and red light (flashing in groups 2+1), indicate that the main channel is to the right (markers to be passed on left). Vice versa, cones (green-red-green), top mark green cone and green light (flashing 2+1), denote main channel to left (markers to be left on right).
Beacons in the Cardinal System. The marks of this system show the safe side (quadrant) and the deepest water beside isolated danger point (always offshore). They may be placed as warning of some important navigation point in a channel (a change of direction, a shoal edge, a point where two channels intersect or bifurcate etc.).They may be located at one or several edges in places of danger and bear the designation of the quadrant in which they lie. Cardinal markers must be passed to N, S, E, or W according to which compass point they show, regardless of the direction of sailing. N.B.: The letter for North in Croatia is S (sjever), for South is J (jug), for West is Z (zapad), and for East is I (istok).
Beacons may be anchored buoys or masonry. In shape they may be a post (cylindrical plinth) or spar and are painted in horizontal black and yellow stripes. Their top mark is two black cones. The position of the cones and the kind of light vary according to quadrant as follows: N quadrant both cones pointing up, light quick or very quick white flashes; S both cones pointing down, light quick or very quick white flashes, six in a group separate by a longer white flash and obscurity; E cones base to base, light very quick or quick white flashes in groups of three; W cones point to point, light very quick or quick white flashes in a group of nine.
Beacons of isolated danger. These beacons show that navigation all round the marker is possible. In form the marker is cylindrical with a post, or is a spar; in colour such markers bear black and red horizontal stripes with top mark of two spheres, they may show quick white flashes in a group of two.
Beacons of a new danger. These beacons show a newly discovered hazard not yet on navigation charts or in the List of Lights. Beacons of the lateral or cardinal systems may be used. In the cardinal system the beacon emits short or very short white flashes, in the lateral system the beacon is red or green in colour.
Very important danger. Two identical beacons several tens of metres apart. One of them may have the radar-reflector RACON (Morse sign on the screen about 1 M long).
Safety beacons. These beacons show that the surrounding water is safe for navigation; they indicate the centre of the fairway or channel. These beacons may be used instead of system A to show the safe way towards harbour or shore. In shape they may be spherical or cylindrical, with post or spar and coloured in red and white vertical stripes. The top mark is a red sphere, and there may be white light: isophase, occulting, flashing (every 10 s or Morse code A).
Special informative beacons. They mark a branching of sea-ways, sea-bed exploration or exploitation, the location of automatic meteorological or oceanographic buoys, a zone of naval exercises, position of underwater cables or pipes, sport or recreation zones, garbage disposal zones etc. They have no fixed shape, but must differ from other nautical beacons. They are yellow with a top mark in form of the letter X. They may show a yellow light but of a kind that they might not be confused with any other system of marking.
All the present systems of marking seaways, channels, danger etc. are basic elements of safe navigation. Thus mariners must consult their charts and handbooks with great attention and keep them up-to-date according to the Notice to Mariners.
Navigation lights with their own source of lighting may be shore-based, located on isolated points for navigation direction or anchored buoys. A special place is taken by lighthouses which have permanent keepers, while coastal lights, harbour lights and light-buoys are unattended.
Lighthouses are located in all places of importance for navigation or at places of special danger. In construction and colour they differ from the surrounding objects and are therefore important also for daytime navigation. They usually have rotating dioptric lenses which allows them to emit a powerful light, round the entire horizon. Almost all the lighthouses on the Croatian coast are in radio-telephone contact with centres of information. Almost all important lighthouses emit fog signals which can be recognized by their characteristic sound pattern (length, number of sounds in a group, intervals between sounds).
Coastal lights are positioned on important points, straits, channels, cliffs, rocks, islets, harbours and port entrances etc. Their function is to facilitate navigation in coastal waters. They have fixed dioptrical lens and are automatically lit and extinguished at sunset and sunrise.
Harbour lights are positioned inside the harbour and at the harbour entrance to facilitate entrance and manoeuvring. They are lit by harbour personnel or automatically.
Light-buoys are floating lights anchored on buoys to show shallows or danger points. Usually they have flashing lights, and are activated by timing mechanism or photocell.
Each light at sea has its own characteristic: colour, character, period, height above sea-level, visibility, number and disposition of lights. Detailed information on this is available in the List of Lights and on charts.
The colour of lights is B WHITE (bijela), C RED (crvena), Z GREEN (zelena). When these letters are noted beside the light visibility they denote that light shines continuously. If colour is meant to show the approach to a harbour or through straits then red denotes the left side and green the right side. This however is not always sufficient guide and for individual cases the Adriatic Pilot and List of Lights should be consulted.
Light character shows the way the light is seen: Bl flashing; Bl (Gp) flashing in group (i.e. BBl /3/); Pk occulting; Sj fixed with flashing; Pm alternating etc. The difference between flashing and occulting is that with flashing the light periods are longer than the dark and in occulting the other way round. If the light has a special sector then this is noted beside the character of light.
Light sectors denote areas of safety or danger. It cannot be taken for granted that the dark or coloured sector denotes the danger or the safety sector and so each individual case should be separately considered from charts or the List of Lights. Sectors are marked by the abbreviation ;sekt+ beside the letter denoting the colour (e.g. sekt C).
Period of light, the interval between the beginning of one series of light signals and the beginning of the next also provides information. In navigation lights special attention should be paid to the time period of the light either with a stop-watch or, after experience, counting the seconds.
Visibility of lights is expressed in nautical miles (M) in which the light can be seen from a position 5 m above the sea-level. Distances are given for visibility in normal weather conditions and for clear nights and are entered on charts and in the List of Lights. For example, if the following appears on a chart, B Bl 3 Gp 10 s 16 M or B Bl (3) 10 s 16 M this denotes: white light flashing three in a group, period 10 seconds, light over middle sea-level visibility 16 miles.
These are radio-stations which transmit signals around the whole horizon. They have exact positions on navigation or radionavigation charts (RC for short). Some radio-beacons intended for aircraft may also be used (marked RC Aero). Each radio-beacon has its own station number; name; geographical coordinates; range (mostly about 100 M, local about 20 M); kind of transmission (A1A unmodulated radio wave length; A2A modulated wave length; intermittent radio signals); frequency (standardly 285-325 kHz); identification signal; characteristics (Morse signals); times of starting and duration of transmission and whether it works continuously or only at times of limited visibility (fog); whether it is single or one of a group (in the Adriatic are 3 groups).
The radio-bearing of radio-station can be measured by way of radio direction finder. This bearing is incorrect for radiodeviation and the angle of half-convergence of the meridian (for distances in the Adriatic sea are almost negligible). Data of navigation radio-beacons are given in the manual of RadioNavigational Service published by the State Hydrographic Institute in Split.
@NASLTAB = RADIO BEACON GROUPS (A2A)
@Z_TBL_BEG = COLUMNS(3), DIMENSION(IN), HGUTTER(.0555), VGUTTER(.0555), BOX(Z_DOUBLE), VGRID(Z_SINGLE), KEEP(OFF), L1(R1C0..R1C3), L1(R4C0..R4C3)
@Z_TBL_BODY = TABLE TEXT, TABLE TEXT, TABLE TEXT
Frequency: 298,8kHz Range: 10080M, Frequency: 289,6kHz Range: 10080M, Frequency: 305,7kHz Range: 10070M
KAMENJAK YPH+20,, 26,, 50,, 56, MOVAR YVH+16,, 22,, 46,, 52, MOLUNAT YCH+10,, 16,, 40,, 46
SENIGALLIA SAH+18,, 24,, 48,, 54, TERMOLI TLH+12,, 18,, 42,, 48, S.M. di LEUCA CT H+06,, 12,, 36,, 42
Pta MAESTRA MEH+22,, 28,, 52,, 58, CIVITANOVA CIH+14,, 20,, 44,, 50, VIESTE VSH+08,, 14,, 38,, 44
Above applicable in fine weather; in fog transmit continuously, +, +